Phone cannot read SIM card anymore and overheats

My Samsung Galaxy S20 FE 5G cannot read the SIM card anymore. The phone was purchased refurbished 3 month ago so unfortunately I have no warranty for it. It started slowly, sometimes it would stop connecting to network and reconnect soon, however little by little it got to the point it cannot connect anymore.

• It stills connects to wifi/bluetooth properly
• I tried doing all types of resets possible, as well as optimization, clearing cache, ...
• I had the SIM card changed multiple times, plus it works on other phones
• The phone overheat an abnormal amount, even when not being used it overheats
• The pin in the SIM card slot seem fine at a glance

What is also weird is that when I made phone calls during the on/off network phase, the call would go through for as long as I like (it would not cut me off mid call). I assume this may require hardware replacement, possibly motherboard, but any advice regarding the issue would be appreciated