Trimming aircraft returns to T.O. trim all the time

Ok I am new to the msfs2020 but have had this problem all along and no correction so far. I am unable to put a trim into the aircraft and have it stay as set. it wants to go back to the T.O. position. I have been told to check the auto trim but I have disabled it if I am at the correct spot to do it and still no change. Could someone please tell me where I deactivate it and use more then 2 words and or what else is causing it…this is in all aircraft…Thanks

Skylab0356

What aircraft are you using?