Cross Cluster Search Not Caching

Hi

If I have a couple of clusters, both connected to each other as remote clusters.

If I perform a search against a single cluster, I get the benefit of caching of search results within a refresh interval window, if I I search the remote cluster again I appear to benefit from caching.

As soon as i prefix a search with *:, or concatenate indices, with a comma, i see +5 to 10seconds of latency. Whereas hitting individual clusters I see sub 50ms response times.

Any suggestions on configuration settings on the coordinator nodes or other areas

(To note the latency between clusters is sub 5ms)

Has anyone else experienced these issues with the latest 7.17 release?