when player sprints, and swiches to spectrator mode while doing it, player is locked in the non-sprinting state
simmilarily when player swiches to specrator while flying with an elytra, player will experience increased mommentum while moving in spectrator
Steps to replicate
enter "sprinting mode" in survival/creative/adventure
press F3 + N while not releasing the W key
move around in spectrator mode, pressing ctrl key does not increase speed
Maybe mojang will fix this in 1.20 Pre 2