Hi Toufiq. How much you complicate everything. And how much time is wasted. Why do you need access and video? The problem is easy to reproduce.
You should have JCE editor as default system editor.
Just place text addor in the FRONTEND SPPB editor, save and look at the code in live viewing through Dev Tools. I described in detail all this above (!!!).
One more (SPPB 5.1.3)
Step 1: Place Text addon.
Step 2: Look at the code via Dev Tools
SPPB 5.1.4
Step 1: Place Text addon. Add p tag
Step 2: Look at the code via Dev Tools