When equipping any piece of armor from the hotbar using right-click with a shield in the offhand, the shield will become stuck in the resting position. To fix this, the shield must be removed from the offhand. This seems to be visual-only and doesn't appear in third-person. This does not happen in 1.15.2.
To replicate:
Open any world
Place any shield in the offhand
Place any piece of armor that can currently be equipped in the active hotbar slot
Using right-click, equip the piece of armor
The shield in the offhand can no longer be raised to the "up" position
Thank you for your report!
We're actually already tracking this issue in MC-171484, so I resolved and linked this ticket as a duplicate.
If you would like to add a vote and any extra information to the main ticket it would be appreciated.
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.
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