Creating a sign manually does not add UUIDs

[villermen]

If you add a sign and type out the names manually, no UUID gets added after the added names (like with /lock 3 [playername]).

If you select a sign created this way with the first user being you, the UUID will be added.

[Artoria2e5]

The part that handles the update does seem to try to fill in the UUID. The whole re-doing getSelectedSign thing seems a bit out of place though (shouldn't mess things up still, since it's a cache on the other side).
https://github.com/NyaaCat/LockettePro/blob/8b63feb/src/main/java/me/crafter/mc/lockettepro/LockettePro.java#L204-L210

The code that does it for the first player seems to be in another place:

LockettePro/src/main/java/me/crafter/mc/lockettepro/BlockPlayerListener.java

Lines 72 to 75 in 8b63feb

	// Cleanups - UUID
	if (Config.isUuidEnabled()){
	Utils.updateLineByPlayer(newsign, 1, player);
	}

The main difference between the two seems to be that the "add sign" case performs an ID fetch immediately, while the updateUuidByUsername case does it async (you can't not do it async with all the web stuff). The edit sign case also has some username format checks, but that's unlikely to fail either.