[Update: Water is just not working right.] The Fish Are Gone

Hello everyone, I've been working on my mod on and off for years and when I came back I finally ported it to 1.20 (from 1.12), and I've realized fish are not spawning. I reported it as a bug and was told one of my mobs were taking up the spawning space. However, almost all of my mobs do not spawn naturally and I have no water mobs in the mod. This problem effects fish, squid, AND guardians, but not drowned.

I went back and looked and squid still spawned in the 1.12 version but I checked my first export of the 1.20 version and they were not. I assume this was some kind of error when it upgraded versions.

TLDR: I'm looking for possible ideas as to why the fish don't spawn anymore, shouldn't be one of my mobs filling the cap unless I'm missing something.

Thanks in advance for any help!

[Update]: So, I've now found out that you can't place kelp OR get water in bottles without using a cauldron. Still not sure if this is a me specific bug or not. I will say I have no features that even interact with water so I find this very confusing.

Again, thanks if anyone knows anything about this!