magic boots prevent you from undoing a buy
if your magic boots procc when you are shopping you won't be able to undo your buy. JSYK
2 Comments
Yes because anything that alters an effect prevents undo.
Firing an Ashe ult cross map, buying before the arrow hits will prevent undo when the stun connects iirc, as an example. Triggering a rune will too.
If the game registers you as being in combat then the undo option will be unavailable.
This is not a bug. This is the system working as intended.