Bag fee for TPAC in Polaris
I have an upcoming flight that is an award ticket booked through NH. Starting D1 from SEA-SFO on UA (X), D3 SFO-NRT on UA (I), D4 NRT-SIN on NH (X), and D5 SIN-TPE (I) on SQ. I called United to about checking bags, and the agent confirmed that because my layovers are all < 12hrs, I can check my bags from SFO to TPE. However, she said that she noticed that I have no baggage allowance for SFO-NRT and needs to pay $300 per bag. Although I can check two bags free for SEA-SFO. My e-ticket from NH does show 2pcs for all segments.
The agent said that it might be that the baggage calculator is not showing the correct charge, because my travel is broken up as SEA-SFO and SFO-TPE. She said that it'd be up to the counter at SFO to decide what to do. And if that SFO decided to charge me, I can only go to NH for reimbursement.
Is this normal? And is there a way to verify the charge before arriving SFO?