Documentation for logging 4.8 doesn't mention that is supports logging 5.3 despite the 4.9 documentation saying it does support it.

https://docs.openshift.com/container-platform/4.8/logging/cluster-logging-release-notes.html#openshift-logging-supported-versions

https://docs.openshift.com/container-platform/4.9/logging/cluster-logging-release-notes.html

I'm not sure if 5.3 was released and the 4.8 docs weren't updated to include it. But currently it says only 5.1 and 5.2 are supported.