Please reset network setting of both Sim one by one and than reset all settings of your's device in general management settings also Flight ✈️ mode on n off one time, restart your's device without any Sim in slots, interchange Sim in slots, turn off power saving mode then try to it's again. If you like please accept as a solution it's help to others users also, click on 3dots in my reply section and click on accept solution. Thanks.
As per your concern, we would request you to kindly perform the following steps to resolve your issue.
Kindly check the device in a different location/network coverage area.
Check device network mode settings: Settings> Connections> Mobile networks> network mode SIM1 or SIM2> Select network mode(set device network mode as 5G/LTE/3G/2G (auto connect) mode.).
Check network operator settings: Settings> Connections> Mobile networks>Network operators> Select automatically> OK> Registered on the network. Note: We recommend setting device network operators as automatically.
Kindly check the same SIM card in another phone or another SIM card in the same phone to verify the issue.
Reset settings: Settings > General Management > Reset.
In case the issue still occurs, kindly visit the service center for a physical inspection of your device. You can locate your nearest service center with this given link: https://www.samsung.com/in/support/service-center/
