Oops my bad, didn't set it public till now.

I've got the rest of test chamber 08 glitchless pretty ok, but what goes wrong more often than not is my momentum while jumping through a portal. First attempt here is a crouch jump where it just halts me in midair, you can see my velocity jump from 260 down to 115 as I go through. Second is me trying to inch forward and jump without crouching, going from 75 to 280 in one frame and the third is a regular crouch jump and well, I assume that's a known glitch but I have no idea how I did it. I was holding W through the portal the first and last times, if that helps.

Am I hitting the sides of the portal without realizing? The ceiling? Am I jumping too early or late? This is driving me nuts, any help would be appreciated.