Big fan of xFeed, as you know, and I use it every day

I've just been trying out the latest version on my iPad Air 2, which is currently running iPadOS 15.5,
and also testing on my iphone SE (1st gen), running iOS 15.5.
On my iPhone SE, the new "sort" feature seems to work fine: it pops up its little menu or ordering choices and executes it OK, both portrait and landscape.
On my iPad Air 2 however, I've noticed an odd bug with the "sort" feature: it seems to crash the app every time, in both portrait and landscape mode.
I don't even get the little popup menu - just an immediate app crash.
There's clearly a small problem here.
regards
Simon