I started with 32 words which should be more than enough for a secure side function with one internal 32Bit variabel, but also multiplying that by 4 does not make a difference.
I have not yet found a good way to look back since the stack traces directly back to “signal handler called”
I know that I have seen similar things in the past when SVC was executed with interrupts disabled (as seen in my last thread) but I did not touch those.
EDIT: Looks like my timer tick (I use lptim for ticks) is the culprit, now I “just” need to find out why. I can see that it was promoted by HFSR.FORCED being set but I have no clue why since from my understanding secure context alone should not change priorities.