You could use sheet straps to keep it tucked on the bottom. You can find these at the dollar store. Are you not using the quilt to sleep with?
Here is some info for you
Hi, I usually just tuck the quilt in at the foot of the bed and it stays in place, you could also try the sheet suspenders,
How to Keep a Duvet in Place
Hi Dorothy. I have the same problem with my quilt. I am currently pulling the quilt way up and folding it over. Then I fold the top sheet on top of the folded quilt. It seems to be working but time will tell. Good luck Dorothy.
I just got a pair of sheets that stay on the bed. The fitted sheet has button holes at the foot of the bed. The flat sheet have buttons, so they can be buttoned together. Maybe you can do something like that. You can see my sheets here: https://momhomeguide.com/cozy-fall-bedroom-weighted-blanket/ Or, you could try using Velcro. Good luck!
Could you pin it in a few places with safety pins
You can buy spender clips for the job from the haberdashery isle of supermarket etc. or fit them with velcro type tape and use that or make an envelope to go under you mattress, or maybe go back to using sheets and blankets that you can tuck in. Another thought might be to buy bigger quilt covers and use the access to tuck under the bed mattress......
I have to tuck mine in an do hospital corners because my husband is terrible at messing up the cover. It's a daily thing. UGH
Hello Can it be tucked under the mattress to secure it?
Hi Dorothy: Here's a video that shows 4 ways to keep your quilt on the bed at night. I bet none of them say "Stop moving around!" :) Good luck
Maybe tuck it in to the bed
This might help, it seems to have a lot of suggestions. https://theorganisedhousewife.com.au/organising/bedrooms/how-to-get-the-doona-to-stay-put/