I guess so ? I assume you googled '' benq washed out '' and reviewed any things from them that may help ??
another vid [comments are funny /mean ]..lol...
https://www.youtube.com/watch?v=B63Y6QyVzyw
cant say if maybe a different cable would help if the one your using got damaged and not carrying a full signal from the card to the monitor ?
you did not say if you went back to a older driver for that older card now that its a legacy card ? these new later drivers may not fully work or be compatible anymore and cause this [ may even damage the old card as well ]
thing is all / any monitor can suffer this issue but just seems to me benq has the most ??? [opinion]