Sony CFS 1000 playback issue, winding works

Bought a CFS 1000, wanted to make it look shiny again. Radio works fine, audio is fine, the only thing wrong is the tape player itself. When I play a tape, it spins for a second, but once the tape is pulled tight, it stops. I can very easily stop the hub from spinning without a tape inserted using just my finger, as if there isn’t enough torque to spin it up, while the motor keeps rotating. Rewinding and FF’ing works fine, and has audio output, but once I hit play again it stops spinning. I have checked inside, nothing looks broken, I greased the plastic gears and oiled metal bearings, but still no idea what isn’t working properly to let it play the tape.

Here’s a video that’s hopefully enough to display the issues.

This was taken after cleaning and refurbishment