Inventory slots 7, 8, and occasionally 6 (when starting from the top left as "1") became unaccessible with the cursor, and effectively trapped the item in the slot. The slot also would remain highlighted until the cursor was moved to one of the non-broken slots, as if the cursor was still on it. Upon un-fullscreening to take a screenshot, the issue resolved itself, even when re-fullscreened.
Linked issues
Comments 1
Thank you for your report!
We're actually already tracking this issue in MC-143776, so I resolved and linked this ticket as a duplicate.
However, that ticket has already been resolved. Depending on the resolution, that can mean that it either will be fixed in the next version, or that it is not considered a bug and won't be fixed.
If you haven't already, you might like to make use of the search feature in the future to see if the issue has already been reported.