Otari MX-5050 1/4" 2 Track High End Drop Outs

Hey all! Hoping those of you wiser than me could offer an opinion.

I've had my Otari MX-5050 for a few years, purchased from someone who bought it new and babied it. It works wonderfully and I keep up with maintenance and alignment (I do myself with an MRL tape), but it's had a strange very intermittent issue since purchased.

The left channel, when in record, will randomly experience a dropout of the high end, feels like around 7kHz all the way up, and this issue will come and go within 30-60 seconds. Happens infrequently but enough that it becomes an issue on mixdown.

It happens with different rolls of tape, after cleaning heads, ect., anyone have ideas? Is this a tape path issue? Excess resistance due to dirty contacts?

Thank you for reading, and happy listening!