Hmm, a couple of questions:
1) have you defeated the Tentacluster in the Maw of Mischief? big whipping tentacle that pops in and out of the ground
2) If so, have you tried/can you Dash? hotkey: "Spacebar"
3) if you have defeated the Tentacluster and CANT dash, go back to the boss arena, there should be a jewel you can pickup
4a) if there's no jewel, and no boss, and you still can't dash, it's a bug. May I ask you to make a screenshot of the Collection tab (hotkey: C)?
4b) if you can Dash, you have everything you need to complete the current content. Remember you can Jump first, and then dash mid-air to get extra distance/height.
Hope this helps, if it doesn't please share more info (screenshots of the blocking zones, for example).
Cheers ^^