Grey overlay on Xperia screen

[BrinDun]

My Xperia XA1/ G1321  (Android 8.0.0) has suddenly started showing a grey translucent overlay on the bottom 80 % of the screen. - the only clear bit is the icons bar across the top. All apps still seem to work underneath it.  Also, when I restart, the login screen has a lot of vertical white smear lines across its black background.   The screen has a number of impact cracks at the bottom RH corner but all was still working. The only thing that happened just before this problem started was that I wipe-disinfected th screen and I am wondering if some moisture has got in through the cracks.  Anyone encountered anything similar ? I can see people have reported similar phenomena with other makes of Android phones but the responses they got are not visible or helpful - most  Google answers that come up are about apps with screen overlay permissions, which I don't think is my issue here.  Maybe it will dry out and solve itself overnight ?

[Uliwooly]

@BrinDun 

if the issue was an app overlay, you could boot in safemode, which will disable all third party apps. With that said, I think it is indeed a hardware issue, nw, it could be only an display issue or it could be worst that, such as a motherboard issue. 

The only thing that you could do is to get it inspected by your local support OR if you want to DIY then you could buy an LCD and teardown the phone to replace it. 

[BrinDun]

Thank you Uliwooly for your time and wise suggestions. I had tried booting in safe mode, though I am not at all sure it worked, as I think I was following Samsung instructions. Anyway, it made no difference.
However, I am delighted to report that I think my speculations about moisture ingress were correct; at some point early yesterday afternoon, the display returned to normal and all is fully functional, so I presume that any moisture interfering with the display controllers had simply dried off. Moral (especially if you have a cracked screen), be very sparing and careful with the application of disinfectant fluid in these times.

[Uliwooly]

@BrinDun 

Glad to hear that it's working now

to boot in safe mode:

long press the power button > a pop up menu will appear > long press Shut down > a new pop up option will appear > Reboot to safe mode > ok 

I always keep couple silica gel bags with my phones just in case.