It does seem to be any spot, though I haven't tested them all yet.
I'm kinda scared to do a repair, as the last time I did one, it nearly cooked my machine (machine temps got way too high for way too long) though that was quite a while (and two computers) ago.
Further updates - it appears to be only when on my home lot (reef finery). If I've loaded into any other lot, I seem to be able to fish okay.
It also appears to be only in one particular save. I ran through two days in a differen save - one as my own sim living in Tartosa but vacationing in Sulani, and one as the resididents of Reef Finery, and everything seems to be working.
So maybe not a bug but a weird glitch with how I built the lot or something. Might have been triggered by setting a fishing trap, but I'll have to explore that later.