more than likely you are having a problem with a floating/ungrounded reel motor assembly. The tape provides a conductive path to the chassis with tape, and when non-conductive leader tape goes past, it can cause a charge buildup like a vandergrafe generator if the elements in the path do not provide a bleeder path.
This is not a good idea. making sure the reel is contacting the spindle and shaft is a starting point. But you need to go thru and clean all the contact points of the reel motor assembly.
But regardless, it should not be happening at play speeds anyway. Something is generating a glitch that is getting into the data path and causing the reset.
Alan