Unable to connect to mobile data

[chisquare]

Unable to connect to mobile data switches in and out. My provider is ATT. I moved Sim card to another phone not Samsung and it works well. 

Calls sometimes ring sometimes gets dropped. And when answered the calls break up. 

Unable to use pattern for screen lock because it doesn't show pattern. 

All this happened after the update 

This has been a nightmare 

[bawaji]

I assume there were no issues with the physical SIM card before the update.

You can try wiping the phone's cache in recovery mode, re-seating the SIM card and reset mobile network settings to see if the phone recovers.

[chisquare]

Thanks for your help. I did all that and still had the same issues and since it is an intermittent issue it was difficult to replicate accurately.
I went ahead and used a different phone it wasn't Samsung and it worked fine. I really want to remain on Samsung so I am swapping back.

[bawaji]

Could be a corrupted update. You may want to search for how to redo the update (see if it can be done via Smart Switch while connected to a PC) or take it to a service center if the problem persists.

Good luck!