Server Mod Rejection

[Fabs Space Box]

I’m trying to join modded servers and I’m getting a “Server Mod Rejection” error. It lists all the mods and saying “cannot be found in client.” I’m very new to modding, and I may be wrong, but I thought it was the server’s files. I have all the mods saved into the mods folder, and I was able to join modded servers a few days ago and sooner. It’s only 1.12.2. And 1.14.4 (I’ve only used the 2) works fine and I’m not sure what’s going on.