Hi, and thank you seriously.

You were right: this was a PPC stack issue. The launcher Stack command only affects the 68k side, while the PPC ELF was still using the default ~32 KB PPC task stack.

Your maxstack result, 32756 / 32756, plus the PPC Stack Ptr is not between PPCSPLower and PPCSPUpper exception, pointed straight at the cause. The crypto handshake and GUI text wrapping were overflowing that tiny stack, and the recent changes made it easier to trigger.

The fix is now in code: the MorphOS build requests a 1 MB PPC stack via __stack, so libnix should switch to it before main(). maxstack should now show about 1 MB instead of ~32 KB.

It did not crash on my PowerMac G5 because my account/usage apparently stayed just below the limit, so I was chasing the wrong lead. Your report caught the real issue.

The corrected build is already online in the same release:
https://github.com/kaffeine1/telegram-amiga/releases/tag/os3-alpha-0.0.1

Please re-download the MorphOS archive and test both GUI and TUI on your PowerBook G4 and PowerMac G5. Any feedback on how they behave would be very useful.

Thanks again for testing and digging into it. This is exactly the kind of feedback that makes the client better.