Sorry for my wrong and misleading answer! I tried to downvote it but was not allowed.
I don’t think there is a way to set any style property to ‘Inherited (Parent)’ or similar. To have this would really be an enhancement, imo.
The way I would do it for a single document as long as there isn’t such a feature:
-1- Install the extension ‘Alternative Search and Replace’ which is able to find named character styles.
-2- Create an intermediary characterstyle, say ‘DisposeAfterUse’.
-3- ‘Search All’ for the spoilt style with ‘AltSearch’ and apply the intermediary style to the search result.
-3- Delete the spoilt style
-4- Create that style anew setting only the properties I actually want (prob. reusing old name).
-5- ‘Search All’ for the intermediary style with ‘AltSearch’ and apply the resurrected style.
Having documents going back to a common template I would try to repair the template. Hopefully I would get offered to apply the changes in the template when opening any document based on it next time. (This not tested.)
Good luck!
(The recent edit only addressed some typos.)
See the answer by @ajlittoz .
Another example how important a clear and unambiguous terminology is in this context and generally for software. I never had a hunch ‘Standard’ might be meant to mean ‘Inherited’ here. Supposed it was meant to mean ‘Default’ and never tested (“reverse engineered”) it.
The problem to create an equally clear terminology 1:1 in about 200 locales will never be solved. Bet?