You are using a proxy cache that isn't compatible with some features of the cache plugin and that is most likely the reason for your problems. If you want to use all functions of the cache plugin without restrictions, but don't want to change the hosting provider, then you can use quic.cloud. quic.cloud is a LiteSpeed CDN that provides you with all the functions of the cache plugin including the cache function, but you cannot use the proxy cache with it either. The same applies to AMP.