[2.0.12] Hotbar stuck in selected state in MP when clicking a in-tranfer blueprint (book)

[luziferius]

It is possible to stuck a hotbar slot in a multiplayer game in the "selected"/yellow background state by using blueprint books. In that state, clicking the slot has no effect. It is possible to un-stuck it by using a different slot, which removes the selected state and makes the previously stuck slot usable again.

Similar effect as viewtopic.php?f=11&t=110546&p=602171

Steps to reproduce:

1. Connect to a multiplayer server
2. Open the blueprint library, take a blueprint book. Larger books make it easier to reproduce
3. Assign it to a hotbar slot while it is in transit
4. Clear the cursor.
5. Try to access the book from the hotbar. It'll show a popup notification that the book is not yet transferred
6. Wait for it to complete
7. Try to use the blueprint

Step 5 is important. If you wait patiently until the transfer completes, the UI does not become stuck.

Screencast

[robot256]

Potentially related issue: 117199