Embedding Excel File on Website Fails

Hi, I have an issue with Excel 365 (So, not with the desktop version!):

Can't embed files on my website. The problem is that I cannot determine which cells have to show up on my website. I made a recording of what I run into which you can watch https://www.youtube.com/watch?v=7Xh_wH7qKtc

Embedding a Word document works fine.

Yesterday had a 2 hour support under #1028165556 but the technician couldn't find the solution although he really tried hard to fix it. So he send me to this tech community.

I hope somebody can help me here.

MacOS Big Sur 11.5.2
Excel Desktop Version: 16.52 (21080801)

Files:

https://onedrive.live.com/edit.aspx?cid=55b31b014e9d5435&page=view&resid=55B31B014E9D5435!301407&parId=55B31B014E9D5435!301371&app=Excel

https://onedrive.live.com/edit.aspx?cid=55b31b014e9d5435&page=view&resid=55B31B014E9D5435!301408&parId=55B31B014E9D5435!301371&app=Excel


Best wishes,
Kor-Jan