Hi @IBN ,
As per my test, I can also reproduce this scenario on my end. In this case, Unfortunate though it is, I'm afraid that's by design afaik, no way to open the link in the embeded Site Contents page if add a tab using the option "Website". Also, it is currently not supported to embed Site Contents using SharePoint related tabs. In short, there is no way to add a Site Contents page to Teams as a tab. I would suggest posting a uservocie here: https://feedbackportal.microsoft.com/feedback/forum/ad198462-1c1c-ec11-b6e7-0022481f8472. It is a place for customers provide feedback about Microsoft Teams products. What's more, if a feedback is high voted there by other customers, it will be promising that Microsoft Product Team will take it into consideration when designing the next version in the future.
----------
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.