Gaps in 5min-aggregate-history overview

All,

Since two days I see 5-minute gaps in the 5min-aggregate-history of all my sensors. See pictures

The 24h-aggregate history data of all sensors is broken up in 5min chuncks, with 5min gaps inbetween. Intervals start and stop exactly on 5-whole-minute time (e.g. 14:05:00). Sometimes longer chuncks are recorded (5,10, 15, 25 mins).

The non-aggregate history data (when clicking on Show More link) looks normal (does not have the 5min gaps)

The problem seems to happens with all sensors (wifi/MQTT, Zwave).

Side info:
The HA-machine, is running in a VirutalBox instance.
Few days ago, I rebuilt the VirtualBox host (Win11). After completion I restored a backup of the VM. I don't believe I made changes in the HA VM configuration itself.
I'm also not sure if the problem started directly after the the VM host was rebuilt (as only 24h is shown).

Any suggestion for troubleshooting?