Decades ago, I did a "first flight of the season" in a ASW-20. Normal preflight of, "cup hand around tail probe and blow" yielded sorta normal needle movement.
At about 200', airspeed was low (glider felt solid), so continued flight.
Flew for a couple hours, landed fine, derigged.
Found a rodent had chewed through a pressure tube. A quick blow looked fine, steady state had a leak.
I had reverted to, "does it look good, does it feel good, does it sound good?".
Decent short cross country, woulda sucked for a competition.

So, unless IFR, revert to basics, hopefully you were taught the basics...... IFR stresses, "believe the instruments, verify what is correct".