Same problem here, I'm only seeing about 2-3 minute of perf. data in the "Realtime" charts in one host of a two host deployment (Enterprise Plus license), the other host is A-OK. Currently running the HPE-customized install at build 13473784. Doesn't matter if I look in vCenter or log in directly to the host at "/ui". FWIW historical data/rollups seem to be perfectly fine...for example looking at Last Day in vCenter does show me the last day with no gaps. FWIW I also checked the size of the actual in-mem stats collection file (out at /var/lib/vmware/hostd/stats) and it's clear (both hosts) based on timestamps that the file is being updated...also the file sizes on both hosts are roughly the same size.
Based on above (Last Day working fine, file updates taking place, approx. same amount of data in both files) I'd guess this is a display issue, not a data collection issue.