The first inline LaTeX in a paragraphe shows a problem as illustrated in the screen capture below.
The inline text appears on a separate line as regular text and is then repeated as LaTeX formatted text on a new line. The second inline LaTeX does not show this feature.

Joplin version: 1.0.195
Platform: Mac OS
OS specifics: Catalina 10.15.4
This issue has been solved on the latest master branch. Should get it in the next release.
I met the same problem. Thank you for your bringing up the bug!
I believe that should be fixed in the latest release. Please check and let us know.