Alongside this, please change the network connection mode to 2G, to see if this helps. You can do this by heading into Settings > Connections > Mobile Networks > Network mode > tap 2G.
Also, please try starting your phone in Safe Mode and monitor if the same issue occurs. This mode will temporarily disable most third party apps and allow the phone to run on its most basic interface. To do this, hold the Power button > Hold onto the Power off icon > Tap Safe Mode, then to exit the mode, simply restart your phone.
If you're unable to receive calls whilst in Safe Mode, I'd recommend getting your phone inspected by one of our engineers. To arrange this, please reach out to my colleagues either by phone or social media: https://www.samsung.com/uk/support/contact/