Steps to reproduce the issue

Article options / tab Articles / set Intro Text to Hide
Article options / tab Integration / set Include in Feed to Full Text
Create an article with intro text 'AA', insert a Read more and add text 'BB'.

Expected result

Look at the html result on the website and view the full article. Only BB is shown.
Look at the feed result and only BB is shown.

Actual result

Look at the html result on the website and view the full article. Only BB is shown.
Look at the feed result and now AA + BB is shown.

System information (as much as possible)

Joomla 3 and 4

Additional comments

I do understand that Full article = Intro + Rest. But as the option states in the hint-text (J3): If set to Show, the Intro text of the Article will show when you drill down to the article. If set to Hide, only the part of the article after the 'Read More' break will show. That makes: Full article = Rest. And the feed does not obey that rule.
Can this be solved?