I am using the current version of JCE on Joomla 3.10.6. I've used JCE for many years.
I have a client who has flushed out a bug while using the editor.
The article only contains several lines of links to PDF documents. If the cursor is placed at the end of any line, and enter is pressed to create a new line, the current link is extended to the new line, as shown in the screenshot here: