That looks a little loose to me.... could be leaking air, almost certainly really.....
If you want to put in the effort,... work it till you get a tighter fit. A little drillin', schoochin', twistin',...
mine butts up tight to the header-stop,... less angle, and no leaks.
I put it on and off about 5 times.... no easy ways or shortcuts,... You just gotta' get determined...
If it bothers you,... you'll put in the effort...
If it don't, you won't...
some of us are wrenchers..
some of us are riders..
some of us are both...
Some of us will give you better advice...
I just bumped you...
Peace