I am still familiarizing with a newly acquired 150.
The other day I flew on a chilly evening just above freezing.
I applied flaps in the pattern, and when I landed, the flaps didn't want
to retract
I had earlier exercised the flaps on preflight without problem
and before the plane was put away, the flaps went up OK.

I guessed that the actuator froze up, so it probably needs lube to keep
the water away.... The flap motor fuse checked OK of course...

Any thoughts?

Brian W