Can you please let us know if any of the below workarounds help:
1. On refreshing the contents of the folder (where these indesign files and idml are saved), the icons of indd and idml files should appear again
2. On the 2nd launch of InDesign the folder icons should reappear.
An error occurred while saving the commentAnonymous commented
Same issue, ridiculous it's taking so long to remedy. Highly irritating.
Thank you for your patience all this while.
This issue is now fixed in the latest update (Id 14.0.1) of InDesign CC.
If you are unable to see the update notification yet, open the menu (three dots) from the top-right of Creative Cloud desktop application and click on ‘Check For App Updates’.
Once the update button is shown against InDesign CC, click on the button to update your InDesign to Id 14.0.1 for the fix of the issue.
Do let us know in the comments, if you face any problem with the new update.
List of fixed issues can be found at: helpx.adobe.com/indesign/kb/fixed-issues.html