The Type Certificate Data Sheet shows a McCauley B3D36C442/80VSB-1 propeller, at least for the T182T with a Lycoming TIO-540-Ak1A powerplant.
One should consider adjustment on the governor; if the minimum governing RPM is set to high, the governor will have too narrow a range and will easily slip out of the governing range at reduced power...resulting in the engine defaulting to the (in this case) low pitch stops.
Sludge buildup in the crankshaft sludge tube, oil passages, dome, or even governor assembly can result in sluggish operation or failure to operate throughout the full range.
A bypassing oil transfer bearing with a significant rate of leakage can cause problems, also. Whatever the case, it must be thoroughly investigated and addressed before flying the airplane again.