I installed synaptic manually, after I noticed that after upgrade it was gone. Also You can try aptitude, it was also part of Mint, I don’t know right now if it still is (I guess You could install that manually too)

It’s no longer a dependency of Mint’s Software Manager, so it’s not “needed” in the way it used to be, but if you need to use it for its own features (which it sounds like you do), you can just install it again anyway.

Either use the Software Manager or

Sudo apt install synaptic

sudo apt install synaptic not an option anymore?

Anyway, if you like synaptic, you might like aptitude, which has a TUI that is quite similar to Synaptic’s GUI. (Aptitude is the OG though)

Isn’t it just sudo apt remove package name? I’m not even close to an expert but had to do it the other day

Ok, I think what we’re supposed to do now is this: Go to the Update Manager>Edit>Software Sources>Maintenance and either “Remove foreign packages” or “downgrade foreign packages.” I think this’s been there for a while now, just never used it before.