Tobi carseat - harness difficult to tighten

[ScotGirl]

I have recently bought a Maxi Cosi Tobi car seat for my 11mth old.

I'm having problems with the harness - it is difficult to got a tight snug fit - the harness seems to loosen one my ds is in.

I feel his head is a lolling about a bit.

Anyone else had similar problems - is there a knack that I've not worked out yet?

I've got the maxi cosi priori, but they look similar.
I put dd in her seat, fasten the harness loosely then give the strap a good pull.
I find that a downward pressure helps me to get a good tight fit with the harness.
I always loosen the harness before I put her in it, then tighten it when she's in.
Hope this helps a bit