On mine, I pushed on the handle, like you're unlatching it and at the same time, spray silicone lube or WD40 in all three openings. You can also use WD40 with a tube (straw) attached and spray the post at the top, allowing it to run down the post. That was enough to loosen up mine.
I've never removed it, but you can probably remove the chrome cover and spray lube the assembly. While it's off, file/sand the sharp edge.
Don & Mary
2019 Newmar Dutch Star 4018 (Freightliner)
2019 Ford Raptor