MacBook Pro 2019- blank screen but external monitor works

The screen/built in display on my 2019 MacBook Pro 13" has stopped working. The screen is totally black, no lights or anything however I can still use an external monitor and everything else seems to be working fine. Occasionally the screen starts working again, this seems to happen after I have left the laptop turned on but closed and haven't used it for at least 24hrs, it will work for anywhere between a couple of hours to a few days before it stops working again.

I think it is a software issue (not a hardware one) because

-When I check the display settings (while using an external monitor) it only shows the external monitor listed under displays, it's as if it's stopped recognising the built in display.

-There has been no flickering or issues with the screen when it does work. It never goes blank or stops working while I'm in the middle of using it. It's only once I've stopped using it (presumably its goes to sleep), I will come back to use it some time later and find the same problem.

I have already attempted (multiple times)

-shutting down and restarting

-checking the brightness settings

-resetting PRAM/NVRAM

-resetting SMC

-restarting in safe mode

-reinstalling the OS

Other things to note

-If I access the laptop through chrome remote desktop, unplug the external display, and go to the display settings it does list the built in display under displays (but the screen is still blank).

-When the screen started working again after the first time this problem occurred, I went to the display settings and selected the built in display to be the primary display, at the time the external display was selected as the primary display. The screen then worked for a number of days and I assumed this had been the problem, but unfortunately it didn't last and the screen went blank again.

The only solution I'm aware of that I haven't tried is to open up the laptop, disconnect and reconnect the display adapter. however I don't have the correct screw drivers and I'm not so confident with hardware so I'm very hesitant to do this and potentially cause more problems.

There have been a couple of similar questions asked about this in the past, but not for over 10 years and none of the solutions have worked for me so I'm hoping someone might have found a new solution in the meantime!