If you use the looking glass while walking and then go out of it, you will continue walking until you press the same walking key(s) again. Using the looking glass a second time also stops it.
Pretty sure this is because MC doesn't handle not receiving keypresses well when something interrupts it, like the various ways to trick it into thinking a key is held-down when it no longer is.
If you use the looking glass while walking and then go out of it, you will continue walking until you press the same walking key(s) again. Using the looking glass a second time also stops it.
Version: 1.16.5-1.13.12