some brokers show strange best bid-ask in pre-market or even during regular hours. Until a few minutes ago Ameritrade showed 0.033-0.029 b-a but 0.033-0.0348 the their L1 Streamer.
Sometimes you will see difference between L1 best quotes and L2.
don't worry too much and don't try to draw conclusion based on pre-market quotes imho. (in pinky land)