Inline custom tag toolbar skips when moving cursor outside RTE

Precondition:
Inline custom tag defined

Steps:
1. Create new content which contains RichText field, e.g. Folder.
2. Type some text.
3. Add inline custom tag.
4. Type some text in custom tag
5. Move cursor outside RTE.

Actual result:
Toolbar skips, see recording: http://g.recordit.co/Oa9wilSLCK.gif