Android 5G SA no data
5G wireless network providers across the United States and elsewhere are turning on 5G standalone mode (SA), that can enable significantly more data bandwidth and lower connection latency. Some phones, even recent phones, are not properly capable of supporting 5G SA even though they work fine in 5G NSA (non-standalone mode) that operates like 4G LTE. Recent Android releases and carrier updates have disabled 5G SA for certain phones that previously had 5G SA enabled due to data connectivity problems when the carrier enabled 5G SA. A symptom of lost data connectivity, possibly due to 5G SA incompatibility, is the phone signal showing 5G signal bars with an exclamation point.
What may possibly but not always help is to turn off 5G in the phone network settings by setting “Preferred network type” to “LTE” or similar instead of “5G”. This may force the phone to use 4G LTE instead of 5G, which may work better for data connectivity. However this does not always help. If a newer phone on the same network carrier works fine with 5G SA, then the phone with data connectivity problems may need a software update or carrier update to fix the problem, or simply a newer phone may be needed. The Network Cell Info app can show the network type and signal strength, and may help diagnose the problem.