Is this typical for new soffit baffle installations?

Twenty-ish years of crawling attics here, and I can tell you what a correct baffle install looks like so you can judge for yourself. The baffle should sit snug against the rafter bay sides, stapled to the rafters down its length, and the channel at the top should stay open, maybe an inch or so of daylight between the baffle and the sheathing. The whole point is that air comes in the soffit, rides up along that channel, and feeds the ridge or roof vents. If the top of the plastic is pinched flat or crushed against the decking, that channel is choked off and you're getting almost nothing through that bay.

The compression you're worried about is usally on the way to the roof vent, but the real seal often happens where the side of the baffle meets the house structure. I did a project a few years ago where the contractor rushed the sealing around the sides, and it felt loose. The only reason my installation stayed sealed up was that I insisted on using that closed cell foam tape around the edges before snapping the baffles in place. It fills those tiny irregularities in the siding and sheathing much better than just relying on a tight plastic fit.

When it comes to the edges, the biggest issue is often the perimeter seal around the baffle collar. If that side isn't packed tightly against the roof sheathing, you're essentially creating a localized pressure drop. On a project I did last year, we measured the CFM and found that if the baffles were only partially sealed, we were losing about 25% of the intended air exchange rate for that specific bay. Make sure the contractor is using actual insulation barrier tape or appropriate caulk at the intersection with the drywall or sheathing.

Update: So after reading the reply about stapling them down the rafter bay, I went back up and checked mine with a flashlight. Turns out a few are barely attached at all, so I shot some staples in myself and that part feels solid now. What I still can't figure out is the top end, where it runs tight to the sheathing. Is a bit of compression up there normal, or does that choke off the whole channel?