The only problem as far as internet is that (To my knowledge) you can only run a cheat happens trainer on Far cry 5 while playing offline. If you attempt to run the game while connected to the internet with a cheat trainer it closes the game.
Headed to bed now, just got off work from 2nd job. I will try removing bitdefender entirely tomorrow and see how that goes.
[Edited by wiccanegyptians, 2/11/2019 7:33:29 PM]
Just to cover all the bases. You mentioned not being able to use a CH trainer online with FC5?
I bought the game on Steam and I never disconnect the net or use the offline key. I just first run the trainer As Admin while, as noted in the Readme.txt, making sure that the game is not yet running.
Then I press F2 to open the Folder Browser so I can select the root directory that the FC-5 game is installed in. For me, that's: \Steam\steamapps\common\FarCry5.
At the main menu for FC-5 I press F-1 and that's it. I'm on my 2nd play thru (NG+) now and I've not had any problems using the trainer at all.