Hi, Lukasz.
Sorry for not posting my findings back then. I wasn't able to reproduce your issue and thought I'll get back to it after some time for another attempt, but it slipped my mind.
What happened is I encountered the very same issue in latest build myself. Here is how it looked like in my case: I used a name containing spaces for the script. Script's name you specify there also serves as OIDC acr, and it seems like oxTrust won't allow it to contain special characters - but instead of explicitly saying so, it just rejects your edits altogether (so if you change some other properties on the script's page, it will ignore them too; that could make it seem like you can't update script at all).
Could you may be confirm that's the issue you also encountered? I'll create github issue for it, meanwhile, it should provide some hint about what happens ofc.