I will admit that I don't use a torque wrench and that I have many that lose zero very quickly.
I do mount scopes professionally. The most common issue I see on scopes is that the screws have been torqued too much. That is where a torque wrench comes in handy but it is not absolutely required most of the time.
Your quote above is intriguing. That should not be happening. What brands and models of scopes are you using? Your issue could be the scope, rings and/or bases or the rifle. Each potential issue needs to be eliminated systematically. Your quote keeps resonating in my head and something tells me it is the key. Feel free to PM me with your phone number and we can talk about it.