I don't think this issue is fixed. It still affects 1.17.1 and all the way up to 1.18 Pre Release 5. I was testing this issue since you can sneak on ledges like this and not fall off even when with a high X/Z velocity but a low enough Y velocity to not launch over the 0.6-block threshold placed above blocks. This is especially an issue with servers/map-making when trying to launch players off platforms which they can just avoid by sneaking.
I attached a video showing it.
This issue also affects up to 1.18 Pre-release 5. I was testing this since this stuckness prevails even when players are launched with high X/Z velocities but Y velocities too low to launch them over the 0.6-block threshold (which is an issue with server plugins/map-making when you want to launch a player off a platform which they can just avoid by sneaking).
I attached a video showing it.
This issue is related to bug reports MC-199313 and MC-200282.