Arrows refuse to be relocated within inventory or relocated out of inventory after running out and collecting ones dropped by skeleton. Also can not add any arrows to inventory or craft any arrows while this is happening. I only play single player survival PS4 (for now) so I am unsure if this effect other areas.
To recreate this;
Add a full stack of arrows to inventory.
Slay hostile Mobs, using all arrows from inventory, be sure to kill a skeleton.
Pick up arrows dropped by skeleton (and all other spoils of war)
Try to move arrows to new inventory slot.
To fix in game;
Use all picked up arrows ( just into a wall for later collection)
Add a full stack of arrows to your inventory
Collect arrows from step 1 ( you will be able to move them at this point)
Another option
Save and Exit
Reload world
Took my smooth quartz slabs, but not the Blackstone slabs or the Blackstone wall blocks. Bedrock 1.16.221