Out of memory error after upgrade to 8.4

[andiMenge]

I tried to migrate from 7.2 to 8.4, but the container fails with an out of memory error:

unifi       | [0.006s][warning][os,thread] Failed to start thread "GC Thread#0" - pthread_create failed (EPERM) for attributes: stacksize: 2040k, guardsize: 4k, detached.
unifi       | #
unifi       | # There is insufficient memory for the Java Runtime Environment to continue.
unifi       | # Cannot create worker GC thread. Out of system resources.
unifi       | # An error report file with more information is saved as:
unifi       | # /usr/lib/unifi/logs/hs_err_pid6.log

I've tried setting new env vars with 8.4, but it seems to have no effect.

environment:
      - JVM_INIT_HEAP_SIZE=512
      - JVM_MAX_HEAP_SIZE=1024
      - UNIFI_JVM_EXTRA_OPTS="-Xmx1024M"

I'm on a PI4 with 8GB MEM w/ around 6GB free memory