Happening to me right now, I let the plane to a holding pattern, but now displays are unresponsive, buttons are clicking (by sound), but doing nothing, sadly.
Only thing seems to be working is the display switch like on the screenshot :-(
Hey, happened me yesterday, FS2020.
I forgot to load loadsheet via simbrief and clicked to refuel slowly (no number was given). It was getting refuelled.
Then I loaded simbrief loadsheet with 73500 kgs, but the refuelling continued on and on. Even when I tried to taxi, it was still showing more and more fuel.