[BUG] Cannot generate into richtext when the source mode <> #776

Describe the bug
I found the bug when i write <>something</>, in source mode, then i switch into rich text, i getting error in dev tools

Reproduction
Try go to live demo, I also getting this error in there

To Reproduce
Steps to reproduce the behavior:

1. In live demo, switch into source mode
2. add something that begin <>, into end </> for example <><p>test</p></>
3. Switch to Rich text mode, the error wil show
4. After error, I cannot continue my source, the result will stuck in error when i switch to rich text

Expected behavior
If my source wrong, tell the error like this

Browser Chrome