really not clear to me what really problem with centering you have. Look to Controls inside cfg of sim for first to see you have all cfg correctly. Set some dead zone if need. MSFS has now bug what make some problems with controllers axes position. You can observe that after hit ESC in flight for a while and return to sim, your axes aren’t correct as you have now set, they are at 50% set by sim what is bug. Maybe this is problem what you still didn’t discovered. If you have other problems as mixed assignment of controls and buttons/keys you need carefully check all isn’t overwrited by other controls.
I am unsure as to what your true problem is but it could well be that your controllers need to be calibrated in Windows. I suggest a look at Simhangar You Tube channel and go to his “How To” series. He has recently released a video explaining how to do that Windows calibration (simple task) and how to manage the control sensitivity settings within the sim. Unlike many Youtubers, Mark doesn’t gabble his delivery is calm, logical and methodical.