How to revert an entity from metered to non-metered?

I have been modifying a couple of pre-existing custom integrations, among others to add the necessary attributes to get long-term statistics.

By mistake I set last_reset on too many entities, and the statistics changed to metered.
5 energy entities, rather than just one with the total/accumulating value.
Although I have removed this attribute on those entities that shouldn’t have it, the statistics continued to see it as a metered entity

At first new records appeared in the statistics table for those 4 entities every hour. But with sum only, rather than mean, min and max.
After all of the things I have tried, it has now stopped adding records to statistics, but only for these 4 entities…

What is the normal way to revert such a change? (remove last_reset, or is it stamped on an entity forever)

It seems to be the recorder updating the statistics. Can I somehow reset this?

Found the explanation here.

Long-term statistics is not gathered for device_class energy unless it is a total value (metered).