At shadow start, the connection is "somehow shaky"

[stdedos]

Describe the bug

/usr/lib/python3/dist-packages/paramiko/transport.py:220: CryptographyDeprecationWarning: Blowfish has been deprecated
  "class": algorithms.Blowfish,
2024-01-31 22:21:24,292 serving html content from '/usr/share/xpra/www'
2024-01-31 22:21:24,292 wrote pid 3402000 to '/run/user/1000/xpra/1/server.pid'
2024-01-31 22:21:24,407 created unix domain socket '/run/user/1000/xpra/h-1'
2024-01-31 22:21:24,407 cannot create group socket '/run/xpra/h-1'
2024-01-31 22:21:24,407  [Errno 13] Permission denied
2024-01-31 22:21:24,408 created unix domain socket '/home/u/.xpra/h-1'
2024-01-31 22:21:24,409 created unix domain socket '/run/user/1000/xpra/1/socket'
2024-01-31 22:21:24,422 notification forwarding is not available
2024-01-31 22:21:24,422  the interface is already claimed
2024-01-31 22:21:24,438 python-zeroconf: '::' IPv6 loopback address is not supported
2024-01-31 22:21:24,468 capture using XImageCapture
2024-01-31 22:21:24,477 xpra is ready.
2024-01-31 22:21:24,477 xpra shadow server version 5.0.5-r27
2024-01-31 22:21:24,540 watching for applications menu changes in:
2024-01-31 22:21:24,541  '/home/u/.local/share/flatpak/exports/share/applications'
2024-01-31 22:21:24,541  '/var/lib/flatpak/exports/share/applications'
2024-01-31 22:21:24,541  '/usr/share/applications'
2024-01-31 22:21:24,541  '/var/lib/snapd/desktop/applications'
2024-01-31 22:21:24,583  uid=1000 (u), gid=1000 (u)
2024-01-31 22:21:24,583  running with pid 3402000 on Linux Ubuntu 20.04 focal
2024-01-31 22:21:24,584  on X11 display :1 of size 1920x1200
2024-01-31 22:21:24,644 New socket connection received
2024-01-31 22:21:24,644  on '/run/user/1000/xpra/1/socket'
2024-01-31 22:21:24,690 GStreamer version 1.16.3
2024-01-31 22:21:24,731 New socket connection received
2024-01-31 22:21:24,737  on '/run/user/1000/xpra/1/socket'
2024-01-31 22:21:24,740 Handshake complete; enabling connection
2024-01-31 22:21:24,789 Python/GTK3 Microsoft Windows aero client version 6.0
2024-01-31 22:21:24,790  connected as 'u'
2024-01-31 22:21:24,790  OpenGL is disabled
2024-01-31 22:21:24,815 shadow server: setting default keymap translation
2024-01-31 22:21:24,890  client root window size is 4480x1516
2024-01-31 22:21:24,914 client   1 @04.843 Xpra shadow server version 5.0
2024-01-31 22:21:24,916 client   1 @04.843  remote desktop size is 1920x1200
2024-01-31 22:21:24,916 client   1 @04.843   :1.0 (508x318 mm - DPI: 96x96) workarea: 1848x1173 at   72x27  
2024-01-31 22:21:24,916 client   1 @04.843     LGD eDP-1        (336x210 mm - DPI: 145x145)
2024-01-31 22:21:26,242 client   1 @06.155 running, 1 windows
2024-01-31 22:21:26,242 shadow server: setting default keymap translation
2024-01-31 22:21:26,627 loaded 98 start menu entries from 13 sub-menus in 2.0 seconds
2024-01-31 22:21:32,797 printer forwarding enabled using postscript and pdf
2024-01-31 22:21:32,815 Warning: not adding duplicate printer 'OneNote (Desktop)'
lpadmin: Printer drivers are deprecated and will stop working in a future version of CUPS.
2024-01-31 22:21:32,820 client   1 @11.858 server is not responding, drawing spinners over the windows
2024-01-31 22:21:32,929 client   1 @12.858 server is OK again
2024-01-31 22:21:32,930 the remote printer 'PDFCreator' has been configured
2024-01-31 22:21:32,967 some GStreamer elements are missing or unavailable on this system:
2024-01-31 22:21:32,967  amfh264enc, amfh265enc
2024-01-31 22:21:33,042 31.1GB of system memory
2024-01-31 22:21:33,052 started command `nohup systemd-inhibit --what=handle-lid-switch sleep 1d >/dev/null 2>&1 & inhibit_pid=$! ; xpra xwait ; kill -9 $inhibit_pid ; nohup systemd-inhibit --what=handle-lid-switch sleep 5m >/dev/null 2>&1 &` with pid 3402372
2024-01-31 22:21:33,055  automatic picture encoding enabled, also available:
2024-01-31 22:21:33,055   h264, vp8, png, png/P, png/L, rgb24, rgb32, jpeg, jpega, scroll
�[0;1;31mFailed to inhibit: Access denied�[0m
2024-01-31 22:21:38,860 client   1 @18.765 server is not responding, drawing spinners over the windows
2024-01-31 22:21:39,110 client   1 @19.015 server is OK again
2024-01-31 22:21:43,873 client   1 @23.765 server is not responding, drawing spinners over the windows
2024-01-31 22:21:44,118 client   1 @24.015 server is OK again
2024-01-31 22:21:50,490 Warning: delayed region timeout
2024-01-31 22:21:50,490  region is 15 seconds old, will retry - bad connection?
2024-01-31 22:21:50,491  32 late responses:
2024-01-31 22:21:50,491      28 jpeg :  13s
2024-01-31 22:21:50,491      29 jpeg :  13s
2024-01-31 22:21:50,491      30 jpeg :  13s
2024-01-31 22:21:50,491      31 jpeg :  13s
2024-01-31 22:21:50,491      32 jpeg :  13s
2024-01-31 22:21:50,491      33 jpeg :  13s
2024-01-31 22:21:50,491      34 jpeg :  13s
2024-01-31 22:21:50,491      35 jpeg :  12s
2024-01-31 22:21:50,491      36 jpeg :  12s
2024-01-31 22:21:50,491      37 jpeg :  11s
2024-01-31 22:21:50,491      38 jpeg :  11s
2024-01-31 22:21:50,491      39 jpeg :  10s
2024-01-31 22:21:50,491      40 jpeg :  10s
2024-01-31 22:21:50,491      41 jpeg :   9s
2024-01-31 22:21:50,491      42 jpeg :   8s
2024-01-31 22:21:50,491      43 jpeg :   8s
2024-01-31 22:21:50,491      44 jpeg :   7s
2024-01-31 22:21:50,491      45 jpeg :   6s
2024-01-31 22:21:50,491      46 jpeg :   6s
2024-01-31 22:21:50,491      47 jpeg :   5s
2024-01-31 22:21:50,491      48 jpeg :   4s
2024-01-31 22:21:50,491      49 jpeg :   4s
2024-01-31 22:21:50,491      50 jpeg :   3s
2024-01-31 22:21:50,491      51 jpeg :   2s
2024-01-31 22:21:50,491      52 jpeg :   2s
2024-01-31 22:21:50,491      53 jpeg :   1s
2024-01-31 22:21:50,491      54 jpeg :   0s
2024-01-31 22:21:50,491      55 jpeg : queued but not sent yet
2024-01-31 22:21:50,492      56 jpeg : queued but not sent yet
2024-01-31 22:21:50,492      57 jpeg : queued but not sent yet
2024-01-31 22:21:50,492      58 jpeg : queued but not sent yet
2024-01-31 22:21:50,492      59 jpeg : queued but not sent yet
2024-01-31 22:21:52,338 client   1 @32.218 server is not responding, drawing spinners over the windows
2024-01-31 22:21:53,288 client   1 @33.218 server is OK again
2024-01-31 22:21:54,033 the keymap has been changed: us,gr,us

After "the keymap has been changed", it looks okay - but that's 15 seconds of being "spinning"

To Reproduce
Steps to reproduce the behavior:

1. server command
2. client command
3. specific action to trigger the bug

System Information (please complete the following information):

• Server OS: Ubuntu 20.04.6 LTS
• Client OS: Microsoft Windows [Version 10.0.18363.836]
• Xpra Server Version: (see above)
• Xpra Client Version: (see above)

Additional context
Add any other context about the problem here.
Please see "reporting bugs" in the wiki section.

[totaam]

There's nothing suspicious here.
Does this still happen if you start the shadow server first, then wait, then connect?

[stdedos]

Does this still happen if you start the shadow server first, then wait, then connect?

Doing one test, yes.

But it feels more like "if xpra/shadow has warmed up once, then it doesn't hiccup".
Or it might be some weird timing issue.

If you see nothing suspicious, let's drop it/