Trouble with middle C as male and agility

I am following along the 30-day beginner course with Jonathan and everytime there is an exercise, I somehow am able to sort of start at middle C, but going back down puts a lot of tension in my throat and can barely do it. 9/10 times it just becomes a vocal fry. I'm not sure what I'm doing wrong here.

I'm still trying to incorporate enough vocal compression, which I find slightly confusion but I think I'm getting it slowly. The breath is always a mystery to me though because it needs buoyancy and engagement, but no tension, which just feels very contradictive. And during the exercises it somehow feels as if my abs become almost pumped and I feel like I can engage them less, even though I'm not crunching down like an ab workout.

The same goes over to the vocal agility. Jonathan says to feel it in the lower pelvic floor and also during that panting exercise (which is a reference to a non-existant video btw). But if I try that and the santa laugh, my belly goes more upwards than downwards, especially if it becomes faster. And then I can't really get up to speed since I feel like I'm flexing in all kinds of different directions haha.

At what point do I need to think about the natural flow of my ab flexion as opposed to try and force it (sort of) down to the pelvic floor?