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 kindly perform the following steps to resolve your issue.
Step 1: Go to Phone Icon. Step 2: Tap More (Three dots). Step 3: Tap Settings. Step 4: Tap Supplementary services. Step 5: Tap Call waiting to enable/ disable.
In case the issue persists, kindly share the report of the problems with a log file. To share a log file, click on the Samsung Members Application (Open Samsung Members Application > Support> Tap on error report > Type your query > Send).
