I've tried to reproduce it in various ways but haven't managed so far: I can install the wifi-ap snap from egde successfuly on my desktop, on a clean 16.04 VM and on clean ubuntu core image (in all cases running snapd 2.23.6).
Also I don't see anything suspicious in the state.json file you attached (but I guess that's expected, the failure you see indicates the state couldn't be updated with provided value, so we will not find it there)
I've tried to reproduce it in various ways but haven't managed so far: I can install the wifi-ap snap from egde successfuly on my desktop, on a clean 16.04 VM and on clean ubuntu core image (in all cases running snapd 2.23.6).
Also I don't see anything suspicious in the state.json file you attached (but I guess that's expected, the failure you see indicates the state couldn't be updated with provided value, so we will not find it there)