Black flashing screen when using discord and FFXIV (not sure if it happens on other games)

[Timelesspa]

l recently purchased a second hand laptop from a friend who didnt have the time to use it, generally my experiences have been pretty good but l ran into a weird issue which l have asked about elsewhere but not getting much feedback so came here to see if l have any luck.

basically l enjoy playing an online MMO (Final Fantasy XIV) now generally l have no issues whatsoever, but twice now when l have dropped on to discord to chat with friends who l play the game with lve ran into a strange issue where my screen goes black and sort of flashes black, the common thread between both times its happened is that the first time l was asked to check if a friends twitch stream was working (l tried playing through the embedded video in discord) and the second time when l visited a room when a discord bot was playing music in the background (the bot links to youtube videos) which l tend to resolve by opening and closing the lid a couple of times then rebooting otherwise it happens again.

l did some random searches that suggested this could be down to GPU elevations of me switching between discord and the game (eg discord using the laptops integrated GPU and FFXIV using the Nvidia) and it not liking it so l added discord to the settings in the nvida control panel, however it happened again (the second instance was the bot streaming music on discord voice channel) so lm kind of left at a loss as to what could be causing it the only other thing l can think of is Bitdefender has some mic protection option but that doesnt require the GPU lm stumped.

has anyone run into this issue or can someone please advice how l can resolve this problem so l can chat and game at the same time without my screen flashing black etc any help would be greatly appreciated.