I've seen some similar posts to my dilemma, but nothing quite seems to answer my problem.
I've set up a simple side-scrolling platform scene and created a small incline sprite with the Solid behavior. I made sure the collision polygon is in place, will full crop of the singular frame.
My character with the Platform behavior moves and jumps as it should on level ground. The odd thing is that, while my character will jump and move just fine while going up the incline, going down is another matter. It will still move correctly while walking, but as I'm going down the incline, any attempts to jump act like it's locked to the platform.
A summary...
Horizontal movement up: Good
Horizontal movement down: Good
Stationary jump: Good
Horizontal movement up + jump: Good
Horizontal movement down + jump: FAIL
I tried to see if somehow creating a "reset" would solve the problem via an "overlap" condition by positioning the character up higher based on its previous elevation (stored to an "old_Y" variable). However, this actually made the problem worse (per my attempt). I find that I don't know how to test if it's actually an overlap preventing the jump or if there's that tiny split second when the character is "falling" from one pixel of the incline down to the next below. Or something else entirely.
Origin points are in place (bottom-center for the character and dead-center for the platform)...if that makes any difference, I don't know.
For the movement controls, I'm using Simulat Platform pressing Jump and the Action Set X to Character.X+CharacterSpeed*dt for the horizontal movement. I'm inclined to think the decimal value of dt is the cause of the problem...but, why on the decline but not the incline?
UPDATE: I changed the horizontal movement to Simulate platform pressing Left/Right and that seems to have solved the problem.
However, from my learning so far, setting movement based on dt can help even during slow PFS rates. Will using the Simulate platform Actions make any difference?