iPhone keeps on searching for service (cell)

Hi all and thank you in advance. My iPhone XS Max recently experienced a nasty fall and the front screen shattered, the bezel and rear glass were fine and sustained no damage. I took the phone to the Apple store and they replaced the front touchscreen with LCD and had them replace the battery while they were in there (it was at 89% and dropping). When they finished they were unable to get the phone to pass diagnostics. In the end I got to leave with the phone without having to pay anything. The one major issue is that the phone continues to ‘search for service’ and eventually times out and displays “no service"

I tried the basic stuff like verifying my sim card works in another phone, cleaning my sim card, resetting my network settings, toggling between 4G and LTE, toggling airplane mode on/off, etc……

When I go to ‘Cellular’ in settings it recognizes the carrier, when I go to ‘General and About’ I can see the modem firmware and the imei number. WIFI, GPS, and Bluetooth work fine.

Is there any chance that I damaged one of the antenna’s or am I looking at a logic board issue? Obviously it’s a best guess scenario, but the antenna’s are fairly cheap and I am capable of replacing them on my own.