See the image, I was adding an image in the article by the button image native fo Joomla! and the bug appeared.
Hi rikaryo
I'm afraid to say that this is not a template issue but it is your joomla editor issue, we cannot debug joomla faults, you can try to ask for support on joomla.org forum or on Jce editor extension support forum.
Regards
I believe it is a bug in the JA_Good template, by the administrator and when a protostar template is used it works correctly. Joomla! 3.9.8 PHP 7.3 Mysql 5 T3 2.7.4 JA_Good 1.0
Thank you
rikaryo Hi Can you check it again ? As i can see the same issue with default Joomla template. I tested this menu item with default Joomla to edit the articles http://prntscr.com/o8u3j0 and issue remain same. You may need to unpublish all 3rd party extension as it can be issue between the editor and 3rd party extension installed on your site.
I also tested JA Good fresh installation with JCE and there is no issue.