New Update - 34.1004.0204.120 causing constant reboot with AT&T SIM card inserted

[Open1Your1Eyes0]

Installed the update version 34.1004.0204.120 just now and now my phone is constantly rebooting if I have my AT&T SIM card inserted.

If I remove the SIM card everything works, even connecting to WiFi everything works fine. The moment I insert my SIM card back the phone immediately reboots within 15 seconds or so.

Other folks are reporting this issue too on the Zenfone subreddit.

Not sure if it is AT&T specific as someone mentioned with a different SIM card (Tello) everything works fine for them. UPDATE - This seems to be confirmed an issue only with AT&T SIM cards.

This is relatively urgent as I completely can't use my phone right now with my usual SIM card inserted (I'm sure as many others as well).

I was on update version 34.1004.0204.88 just before this and everything was working completely fine since day 1 for me so clearly this update caused the issue, this is not a hardware or unique user data issue.

Some additional things I noted - If I insert the SIM card but the phone is in airplane mode then it doesn't cause the issue. If I have no SIM card inserted and use WiFi it also doesn't cause the issue. But if I insert the SIM card in airplane mode AND connect to WiFi then it keeps on restarting again. If I disconnect WiFi and go in airplane mode (with the SIM card inserted) OR remove the SIM card (and connect to WiFi) then it starts to work again. Seems the issue is related when it is trying to connect to the AT&T network directly (via SIM) or connecting to any WiFi network when AT&T SIM card is inserted. Not sure if this issue is an with other carriers as well but this is what I noticed so far.

[Open1Your1Eyes0]

Thank you all for your confirmations. I have just updated the OP to reflect this seems to be an issue only with AT&T SIM cards.

[Codemansgt]

I have tello and att sims and after the update the att causes the phone to softreboot upon connecting to their network. I have the global edition (I think)

[Gutter_Fool]

Coming back to this, I charged my phone and removed the SIM to be able to use other functions and apps again. Probably will take this opportunity to update my backups.
Will be interesting to see how the fix will be applied. Will it be from AT&T or ASUS? Is it a whitelist error, coupled with a coding issue that tells the phone to reboot because it's being denied by the network but the phone is like "hey, that's not right! *restart*"
Will the install fix be along the lines of "With SIM Card removed, connect to a stable WiFi internet connection and click this link here or in an email (or go to System Updates) and download this patch."?

Speculations, speculations... Will be interesting (at least for me 🤓) Just hope it's addressed before the weekend 🤞

[Emsodo]

I made a post about this Tuesday and have yet to hear anything back. 

[Gutter_Fool]

I just went and read your post. Crazy that it's happening to other models AND still only AT&T users. I really hope, when we hear from staff, that the ultimate fix ISN'T to factory reset since it was caused by an update to begin with...