This is not from the COVID virus, it's from the sedation.
It happens a LOT with sedated patients, and no one tells them about it first. It can leave some patients with severe PTSD because the same sedation that causes it also blocks them from communicating about it.
See: https://well.blogs.nytimes.com/2013/07/22/nightmares-after-t... or just search for "sedation hallucinations".