Gravity malfunctioning at lower framerates

In my game when the player jumps he can press the jump key again to glide, a do this by changing the value of gravity when he is in the “gliding or floating” state.

The problem is at lower framerates he will fall faster than on higher frame rates, when at uncapped framerate his initial Z velocity will be something like -74 when you cap it at 30 frames the initial Z velocity will be something like -194, of course this values keep on decreasing until they reach a max falling value at set at -500, this causes the player to be able to glide further away when he has higher frame rates.

The question is, is this intended? is it a bug? anyway to fix this without rewriting gravity?

I can show you the code but it is nothing special its basically just setting values on the movement component of the player character.

Thank you in advance.