When i edit the copyright it does not update in previously published articles

1. In the rss feed importer (see picture 2) I edit the copyright.
2. in previously published articles, the copright does not update (it is always the one that was put before the modification that appears)

Is this normal?

Also the copyright is not displayed correctly on the page: look at picture 1 you could see that the copyright overflows on the right column or there are the modules

Can you look to see where the display problem comes from, please