This just happened to me yesterday as I was getting ready for 6 months of cold weather here in Michigan I couldn't get the hose connection to budge by hand or with channel locks I tried a propane torch
(warming it up a bit) , penitraiting oil a pipe wrench all to no avail !
ended up using a dremel tool with a cut off wheel, splitting both sides of the aluminum and using channel locks to break it loose! Lesson learned 😌

I use teflon tape on the threads and have not had an issue.