Years ago when analogue FM tuners used variable condensers there was a common issue with older units known as "NPR Syndrome". Back then the first four MC's of the FM band were reserved for college / non-commercial community stations and the bible thumpers hadn't started snapping up allocations. This meant there was a fair amount of open space below "92" and many listeners weren't exactly NPR material. The average tuning condenser rarely approached full mesh. Throw in a touch of oxidation and you ended up with a tuner that didn't work below 92 MC's.
The fix was to either clean the rotor ground contact fingers or exercise the tuning knob with extreme prejudice.