Can you reproduce this issue here?
It’s very unlikely that this is being caused by just enabling the rich editor, which just adds the toggle and defers the actual loading of the rich editor and its dependencies to after toggling it.
Can you test if force-closing the PWA and opening it again, or rebuilding your instance, changes anything?
Let us know if you have reproduction steps that work here on Meta, or if you can share your site’s URL (even ir privately).