Inground pool dilemma

[Kenmyfam]

Daughter has 24 foot round inground pool of a distant vintage.
It was refurbished by filling some of it in and using an above ground liner inside it.
Now has multiple issues with the styrofoam from the coping coming out and jamming behind the liner part way down.
My question having reviewed these issues.
What would be the thoughts on us putting a 21 foot round above ground pool in the hole in the ground and back filling the gap between. I personally don't think the current pool is salvageable.
I have only ever had above ground pools previously.
Any and all input will be gratefully welcomed.
Thank You.