@Denis Meusy
Hi,
As far as I know, there is no related known issues has been offered.
https://learn.microsoft.com/en-us/windows/release-information/status-windows-10-20h2
Looks like there are some changes made in the File/Windows Explorer feature and due to which you are not able to see the options.
I would suggest you to leave a Feedback for this product so that our developer team can look into this and check if it can be implemented in the future updates.
https://answers.microsoft.com/en-us/windows/forum/windows_10-win_cortana/search-box-in-windows-explorer-broken/1b752789-fdf0-49ec-8d6b-aab7c64ed255
Hope above information can help you.
============================================
If the Answer is helpful, please click "Accept Answer" and upvote it.
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.