I've been flying my P337 for 2 1/2 years and I have had some landing gear and gear door issues. However, after taking the following steps those issues have stopped:
1) I check the hydraulic fluid reservoir before every flight.
2) Then I pull the circuit breaker to the landing gear motor and manually open the gear doors and check for anything obvious like leaking actuators.
3) I do not operate the gear over 120 knots.
4) I am straight and level during operation of the gear.
5) If there are gusting winds or over 15 knot winds I will reduce speed further before operation.
BTW, sometimes I have had the circuit breaker pop
when operating the doors while banking or exceeding the speeds above. Reset the breaker after leveling.