Just FYI, I upgraded from 7.16 to 17.17beta4 on my LtAP with Quectel EC25-AF modem. It boots up, activates the LTE interface and then crashes. Since that happens at boot, it was just crashlooping before I could really get in an do anything. Reset to defaults, which let me in and wouldn’t crashloop because LTE didn’t come up. Re-configured LTE and … crashloop again. Had to roll back to 7.16.
I only have one of these else I’d try to gather more info, but just FYI in case it helps anyone.