Make sure you have all the parameters set correctly;
FOV Scaling Prefers Scope FOV - Checked
Scale Sensitivity with FOV - Checked
Scope Setting - Normal
Check that you use the correct FOV in the calculator as configured in the game, and set all the sensitivity values according to the calculator.
They might still update how sensitivity works in this game, so if you still have an issue give me all the details (conversion settings, scope, game settings etc) and I'll check it!