So I can still using fastboot boot 3.4.2B-1206 OR fastboot boot the TWRP by manuelbianco to flash the following weekly update?Sadly TWRPs by manuelbianco don't recognize OTA packages for some reason.
You can still try 3.4.2B-1206, OTA works and apparently flashing as well.
I thought the issue I facing just now was using the TWRP 3.4.2B-1206 to flash the latest ROM ?