Installation ? On graco snugride 30 base with kickoff.

I am going to be using my friends car seat for my little one due in just a few weeks (no wrecks not expired and I purchased all new belts and clips Ect through graco). I have a total of three bases to go with it. One that came with it which I had no issues installing- the other two are compatible but they have the built in lock offs they are identical. I have been having issues all day. I can get the base installed and from all instructions and guidelines the belt lock off must be closed even if using latch. At least that's what it appears in the manual. It doesn't specify that it must remained closed with latch but the pics show it. If the car seat snaps on the base with the locks offs closed the seat gets stuck and only way to remove is to take the base out all together flip the seat over and squeeze my hand between base and seat to move the metal seat belt positioner piece away. It's like it makes that part to thick. If you leave it open it does not. so can you leave the belt lock off open if using latch? I understand if using the seatbelt it is required but it doesn't effect the tightness of the latch at all. Is this a common issue? It's been 7 years since I had to install an infant seat and my sons never had that issue. Any help would be appreciated! Now that I'm typing this maybe adjusting the harness to move the metal clip would be best for now since baby isn't here yet- maybe that's what's stopping it?

Hi!

The Snugride30 does have a known issue on the compatible 35 base of sticking when the harness is in the lowest spot as you describe, though it is usually not quite that severe. Loosening may help. If not you may want to use baseless until the harness moves up, unless you want to call Graco and buy extra 30-specific bases. The lockoff does need to be closed.