No need to report the bug.

While trying to find the right place to submit it I found:

https://zero.eik.bme.hu/~balaton/qemu/amiga/

"Bitmap fonts in apps using old gadtools are garbled with ati-vga

This seems to use host data feature of ATI graphics cards which is not emulated by ati-vga. Use -vga none -device sm501 instead."