Let’s do a bit of a troubleshooting process. In your control options, create a brand-new profile that’s blank (nothing bound) for every single hardware that you have on the list and make sure they’re all assigned to have this blank profile active. This will make sure the sim doesn’t receive anything from the hardware.
Then for your throttle, with a blank profile, just bind throttle lever to the throttle axis. If you have a twin throttle lever, you assign the left one to Throttle 1 Axis, and the Right one to Throttle 2 Axis. Otherwise, if you only have a single throttle lever, just bind it to the Throttle Axis command.
Once you do, just test the lever by moving it. You should see the white bar moving. When you place the throttle in a certain position and lift your hands. Check to see if the white bar stays and doesn’t move. If it stays, then you’re good.
Now, you can start a flight with the aircraft of your choosing. Inside the cockpit, without doing anything, try to move your throttle lever and look in the cockpit. Does the throttle also move accordingly? Then same as before, place your throttle in a certain position, and watch the throttle inside the cockpit. If it stays, then you’re good to go.
If you’re already seeing the throttles drift the first time even after you completely done the whole process above, then the conclusion is your hardware issue, because we already eliminated any other potential possibilities.
If everything is all good, all you need to do is to manually bind the other controls one by one. This is the only way to “make sure” that you don’t have conflicting blinds. Because to be honest, as humans it’s easy for us to miss something. Where we can be sure that there’s no conflict, in reality, there could be a conflict somewhere that we missed. So doing the troubleshooting steps above is a more scientific approach to find an issue and resolve the problem through the process of elimination.