Image right-align not working

Hello,
Just another topic (this would should be easier I guess) because it seems like the right-alignement (and left alignment) on pictures do not work. Here’s the issue:

When I’m in the editor I can choose the alignement I want for my pictures and it works just fine : https://nsa40.casimages.com/img/2020/12/10/201210074533197201.jpg
But when I publish my page and go check the result, here is what is displayed : https://nsa40.casimages.com/img/2020/12/10/201210074533371867.jpg

The image is indeed right-aligned but the text isn’t on its left.
How can I fix this so that both are displayed next to each other?

(I have the latest version of WP and of the theme installed, and no additional plugin activated)
Thanks a bunch for your help! ??