Can not save changes using theme editor

I am encountering a persistent issue where any modifications I make are not being saved. I am able to edit documents or entries without any problems, but when I attempt to save these changes, they are not being retained. This issue is specific to certain topics or sections, as I am able to make and save edits in other areas without any difficulties. It appears that the save function fails to execute or complete successfully, potentially due to a software bug or a permissions issue. Please advise on a solution.