Sometime after 1.15.2 guardians stopped spawning

After updating a server, that I am running off of my computer, to a snapshot update after 1.15.2 guardians have stopped spawning in the world. My friend created a farm for guardians and they didn't spawn there and I went to two other guardian monuments I knew of and guardians were not spawning there either. I do not know specifically when it started in the snapshots other then it was about a month before 1.16 was released. I've tried looking into the server files for things like if there was a mob cap or if it was because the server was not on normal which I have left it at for almost a week now. I currently have the server at 1.16.1 and nothing has changed.