Hello! What you are seeing is quite strange indeed. I watched your video, and usually the text under the move tool manipulator that says "slide" only shows up when you hold ctrl + shift (for doing a slide operation), so I'm wondering if something has gone wrong with the tool settings, or the mesh needs to be cleaned up. here's a few things to try:
1. reset the move tool.
with the move tool selected, go to Windows > General editors > Tool settings. This should open the tool settings (if they aren't already open). In there, try clicking the Reset tool button that can be found at the top right. If that doesn't fix it, try step 2.
2. Try deleting the construction history on your mesh.
I noticed you have a lot of construction history on your mesh. This can lead to all kinds of problems, and it's usually best to model with construction history turned off unless you need it on for a reason. First off, please try this step on a COPY of your file first! I don't want you to lose any work. Once you are in a copy of your file, to clean up the construction history on your mesh, just select your mesh while in object mode and then go Edit > Delete By Type > History. This will remove the history of all of the cuts, extrudes, moves, etc that you have done since you started modelling, and leave you with clean geometry.
Let me know if either of those work, and if not we can try some other things as well. Hope that helps!
