I accidentally dropped an item at almost the exact moment I switched from inventory slot 1 to 2, showing the the wrong item dropped. Items ultimately didn't dupe or disappear, likely visual bug?

What I expected to happen was...:
Depending on which item I dropped first, either the slot 1 item should have been gone from my inventory (showing the slot 1 item on the ground) or the slot 2 item should have been gone (showing the slot 2 item on the ground). When I go to pick it up, it should appear in the first empty inventory slot as normal (i.e., slot 1 or 2 respectively)

What actually happened was...:
The slot 1 item (a diamond axe) stayed in my inventory while the slot 2 item (a diamond pickaxe) dropped. However, the diamond axe also displayed on the ground and my pickaxe looked like it disappeared entirely. When I picked up the buggy item, my inventory looked the exact same (slot 1 held axe, slot 2 still showed nothing). But, when I went to mess around with my inventory trying to find the pickaxe, it showed up again as expected/hoped.

If I had to guess, the item I dropped was my pickaxe (slot 2) and it displayed incorrectly as if it were slot 1's item.

Steps to Reproduce:
0. Play a completely clean, vanilla copy of Minecraft (started playing with new install yesterday)
1. Put a diamond axe in slot 1 and a diamond pickaxe in slot 2 (just in case); I was in a cave about to mine some copper or coal ore or something.
2. Select inventory slot 1 ("1").
3. At close to the same frame (I'm not sure which came first, but my guess):
(a) Drop the currently selected item ("q").
(b) Switch to inventory slot 2 ("2").
4. Item 1 will display as both in inventory and on the ground, but item 2 is gone from both.
5. Pick up dropped item-- inventory still looks the same.
6. Updating the inventory somehow (I forget how... selecting 1 then 2 again? swapping item into slot 2 then back?) causes the item that was in slot 2 to re-appear again, correctly displaying the item that seemed to have disappeared.