I just noticed that the debug hotkeys I had were still active- these are disabled in the new hotfix, along with a few other fixes.
If you'd pressed i, you would've seen something even weirder!
Shift is now disabled. I'll see about adding a more proper, less buggy fast-movement option eventually.
Not sure about that with the redworm bug- grabbing an empty spot should just result in covering the spot in question. I'll give it a slight peek.