localtime_r() off by 8 hours

[Miq1]

I am using time.h to have access to the time-based functions. I have two defines as

#define MY_NTP_SERVER "de.pool.ntp.org"
#define MY_TZ "CET-1CEST,M3.5.0/2:00,M10.5.0/3:00"

In setup(), I am trying to set up the time functions by

// Start NTP
  configTime(MY_TZ, MY_NTP_SERVER); 

But when in loop() reading the time with

        time_t now;
        tm tm;
        time(&now);                       // read the current time
        localtime_r(&now, &tm);           // update the structure tm with the current time

it turns out that the time is off by 8 hours. ctime() returns

Sat Mar 27 23:29:20 2021

instead of the correct

Sat Mar 27 15:29:20 2021

What may be the cause?

Oh, by the way: I of course tried different NTP servers and other time zones. The offset is different with other TZ values.

[Miq1]

Found it. I was building with LwIP 1.4 still. Switching to LwIP v2 solved the problem.