@silva8899 the issue is that you are loading multiple versions of Font Awesome still, and will need to disable the legacy version you are still including in your source code: https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css
I’m also seeing additional FA styles coming in from https://teneriffa-aktuell.com/wp-content/cache/wpo-minify/1615713029/assets/wpo-minify-header-4794cd3c.min.css, so it looks like you’re doing some minification that might also be including conflicting styles.
I’m not sure where this is coming from specifically, but if you search your source code in browser you’ll see it, and I suspect you have another plugin/theme that’s generating this. You’ll simply need to disable it somehow, and that should resolve your issue.
Also also, I’m not seeing the latest inline CSS that’s included in the new BFA 2.0.1 update being output on the page, which suggests to me that either 1. you may not have updated to the latest 2.0.1 version, or 2. some of that aforementioned minification (or perhaps some caching) needs to be reset to pick up the new inline CSS.
Please fix these site-specific issues first, and then see if you’re still running into the same issues.