When having a text box inside an auto layout, and setting both the text to right aligment and the auto layout, on the type of new content, the box expands to the right side, being anchored on the left.
Resuming, the right alignment is not having any effect.
Be sure to use your Figma account email, include a short video and the links to an example file, and share it with support-share@figma.com so they can take a closer look.