@SteWers Sorry, but you are not giving any information that allows analyzing the problem. You just refer to a previous statement by someone else about this (I assume it is this one: openHAB 5.0 Milestone discussion - #7 by michaeljoos)
Here is the link to a recent fix that has been made: [rrd4j] Not able to restore values on startup · Issue #18303 · openhab/openhab-addons · GitHub. If this does not solve the issue, please provide logs of the item being persisted and any logs showing the startup.
There has also been other recent discussion about rrd4j: Problems with rrdj4 - #5 by jlikonen.
