Our new HiSense TV began asking for a ‘screen refresh’ occasionally then frequently then daily. The words on the notice warn about doing a refresh no more than 12 monthly. A call on their help line took me through a TV reboot deeper than the one you can call up through settings. It worked for a short time then the problem reappeared. This time they sent out a technician who changed the motherboard and all is now well.
It was an excellent response. That you HiSense.