Twitter Account unable to render card preview

[ELBdot]

Greetings, I have encountered a very strange problem with my twitter account when I try to share a link to my website: It is completely unable to render its card previews. This might not sound like a new problem to you at first, but the thing is, it only doesnt work for THIS account in specific. The moment I post the same link from my second account, it immediately gets shown the way it should be:

Furthermore, when Im logged into my main account ELBdot and somebody else posts a link to my website, Im still only able to view the URL and every twitter card gets blocked. When I log out, the preview images are visible again.

Here are the details: I created my website via wix.com and its main URL is https://www.eleanorbick.de/
At first I thought this was just an issue with my twitter card, so I learned how to add Metatags to my Header Code in wix to fix the issue. And this actually DID help to make a twitter card show up on my ELBdot twitter account.

HOWEVER, the problem with wix is, that adding said Metatags meant I only got a single preview image for every page of my website Im trying to share, including blog entries, which is something Im trying to avoid. When I removed the code, the website actually should be able to automatically generate a preview image for my page like it did above.
But again, for some reason, this doesn’t work for my main twitter account.
I really dont know what to do anymore or what I might be doing wrong, so help would be appreciated! Thank you!