The bug
The tab-completion of command arguments keeps inserting the same value when you close the suggestions by pressing the ESC
key.
How to reproduce
Type or copy the following
/give
Press ↹ (
TAB
)Press
ESC
and thenTAB
twice
→ ❌ It inserts a value; you can repeat this steps as often as you want
Can confirm in 20w51a.