A group of Microsoft Products and technologies used for sharing and managing content, knowledge, and applications.
Dear Vince Taylor,
Good day!!
I understand your concern and to my knowledge, the column settings used at your end doesn’t have any problem and when I checked the behavior by integrating the custom Power Apps form with list, there is no issue in editing the text column enabled with enhanced rich text.
Since you are using the Nintex for creating the List Form in the SharePoint Online List, I would like to request you to post your concern in the related community i.e, Nintex Community (please search for Nintex community in the browser) to get the detailed help from the experts.
Apologies for redirecting you to different Microsoft community as the members in the category posted focus on the users with the out of the box concerns on SharePoint Online and have limited knowledge on Nintex, so to get the fast and better assistance, we have redirected you in the correct path.
Appreciate your patience and understanding. Have a great day!!
Best Regards,
Sophia