Steps to reproduce

1. Install Ibexa DXP v4.1

2.  create a custom tag: https://doc.ibexa.co/en/latest/extending/extending_online_editor/#acronym

3. Create content with rich text e.g. Article.

4. Use a custom tag and try to edit the text in it

Result

Can't edit the text into a custom tag

Expected result

Can edit the text into a custom tag

Note

Custom tag after added has attribute contenteditable="false"