Adjustable frame mattress protector HELP

So this is an out of the ordinary post. We recently splurged on a king size adjustable frame bed. It’s great but I had such a hard time finding sheets that wouldn’t come off the mattress when we adjust the frame to watch movies and get sexy time angles a little better. I finally found some (way expensive but worth it). Now I’m having the hardest time finding a mattress protector for it. Do any of u have the same bed and did u have to find a taller mattress protector than for a regular frame mattress? If u found one, what brand or do u have a link?

I guess I’ve been looking for something 18” deep like I found in tight sheet (or whatever it’s called) but maybe that’s not necessary if the protector goes all the way around with a zipper?I don’t know. I just don’t want to stain the mattress and need the right protector that doesn’t limit the flexibility of it when adjusting the frame.