Surprised I haven't seen it yet here, but LAX/LAS/BOS/IAD/SMF/ATL/etc to TPE is available in April and May for 15k in XN and 80k in JN.
There's no way to see this as anything other than an error fare as you have to route through EWR-SFO on UA871, which just happens to also be the flight number for the afternoon SFO-TPE. The connection time calculator at EWR is broken and shows 0 ground time in the app. The SFO connection also shows funny on united.com.
Credit to
https://www.reddit.com/r/awardtravel..._us_to_taipei/