this block contains invalid content

Love this blocks, but since about a week I have a little problem

I make Infoboxes and all is ok, I save them. But when I edit the post some of the infoboxes have this “this block contains invalid content” message and ask if I want to change it to html.

The crazy thing is, when I check it out it shows the code and how it would change the code, it does not make sinn. It would change this code “viewbox=”0 0 448 512″ height=”80″ width=”80″ fill=”currentColor” xmlns=”https://www.w3.org/2000/svg” preserveaspectratio=” to “viewbBox=”0 0 448 512″ height=”80″ width=”80″ fill=”currentColor” xmlns=”https://www.w3.org/2000/svg” preserveaAspectrRatio=” So it basicly would add double letters.

The more crazy part is that the infoboxes are copies of a infobox and I changed text and link, some are ok, some get this error.

In frontend it works, but in backend it shows this error and the infoboxes are not possible to edit.

Example https://lebenindenusa.com/lebenshaltungskosten-usa/ on the end of article all infoboxes are ok, exept the “kalender”

The page I need help with: [log in to see the link]