incosistency between return types in disassembly/function signature editor vs decompile view

[orangecms]

I am sometimes seeing that the decompile view shows

void foo(void)
{
  /* ... */
}

and yet, in another function calling it, I would get something like

  iVar1 = foo();
  iVar2 = *(int *)(iVar1 + 0x800); // looks weird; iVar1 here was really a function argument

• leaving me puzzled; why the assignment from void?

I then noticed that in the disassembly view in the function signature editor, I would see the return type undefined, and would need to adjust it. Having done so, the calling function correctly reads

  r16_to_stack();
  iVar1 = *(int *)(param_1 + 0x800);

I checked existing issues from the last ~2 years, but couldn't see a similar bug report.
I am on 52aed0a plus the changes in #3006 and I'm analyzing an ARCompact binary that I cannot share for legal reasons.
See https://github.com/orangecms/ghidra/releases/tag/Ghidra_12.1.2-2_ARCompact_build