Delayed data points in charts (rrd4j lag after upgrade to OH4)

After my recent upgrade to OH4.0.0 I have encountered a lag of data persisted by rrd4j (stock settings, no changes to default) observed through charts showing datapoints updated hours previously (the current measurement against the item is correct. The historical readings are eventually persisted but the lag only increases. I have not observed any log abnormalities related to persistence, and did not experience this in the pervious general release version of OH before upgrade.

One quirk of my setup is that there are some things that are not powered consistently (ie the geyser that I’m measuring in this example not be powered for certain times during the day and would miss heartbeat responses during that time)

Is there a way I can increase the verbosity of the logging to assist in investigation of this issue? (am at a bit o f a loss as to how to proceed)

Im running OH release version 4.0.0, on Ubuntu Linux server (VM)

This ended up being due to increased disk IO experienced after upgrading - Solved by enabling access to host io cache on the VM - leaving the post up for anyone experiencing the same issue.