Cant remove tags from items

i use REST API to tag items for using with google assistant.I noticed that 5 random items also had the tag “Lighting” from the start so i want to remove “Lighting” tag from them so they not appear at google assistant home control.I used Rest api twice and successfully removed item tags.But when my openhabianpi restarts the tags on the same items are back on.Is there an other way to permanently remove these tags?

No there isn’t an easy way

The other way is to edit the json.db typicaly located in: /var/lib/openhab2
Make sure you save a back up of the file before editing it. If there is an error in your edit OH will likely not start properly if at all.