Please try FireFox. chrome and FireFox support HTTP/2, IE does not.
If it really is a HTTP/2 compression problem, it will be hard to fix.
We have to find out what exactly happened down the wire.
I am not confident that we could get enough clue to get it fixed without experiment/reproduce the problem ourselves.
If you would like to work with us to get it fixed soon, please contact bug@litespeed ... or submit a ticket,