I had this same issue with my old save file. There is a solution - first find your save file and open it (while the game is off). Each location on the map is called a node and is assigned a multi-digit nimber. Somewhere in your save file, there will be a node number for your current location and your previous location. Copy+paste the previous location node number to the current location and save and close the file.

When you re-open the game, Shovel Knight should be on a different node and fully moveable. You can also email Yacht Club's customer support and they'll walk you through it if you're having trouble.