Resetting all phone settings will cause you more headaches.
Go into your "Mobile Data" settings and disable the "5G Standalone" setting. That setting should NOT be enabled by default. However, it is enabled by default in OneUI 9 Beta 1. Essentially, that option forces your phone to only utilize a true 5G connection. So, if your carrier in your area utilizes an upgraded 4G LTE tower (as is the case in most areas of the US; connection shows up as 5G instead of 5G+ or 5G Next, or 5G Ext, etc), then your mobile data will not work unless you disable the "5G Standalone" option.
Reports related to mobile data connectivity behavior on certain carrier networks during the Beta period are currently being reviewed by the relevant team.
Additional software updates may be provided during the Beta program to improve overall stability and performance.
If the issue continues after future updates, please submit an Error Report through the Samsung Members app with system logs for additional analysis.
We appreciate your patience and participation in the One UI Beta Program.
