The ones that wouldn't go all the way, pull them out and drill it deeper.
The other two, take those out and tighten them up a little out of the wall, then tap them in with a hammer, gently, until they'll bite.
If they're not fixing properly, don't let them stay in the holes. It's only doing a number on yourself when the deck starts sliding and wobbling not long after.
Look at it this way, you haven't burst any bricks yet (I think), so you're doing well. It just needs a bit more tweaking.
I've used solvent based glues for wall plugs before as well. I got REALLY annoyed finding sockets and backer boxes around the house that were close to falling out the walls (quite a few of them were just sticks of wood buried in the wall with one very loose screw involved, it's an old house; before backer boxes). For things I know aren't going to be touched for the next few decades and that will need to be solid, I'll squirt glue into the holes for the plugs, then a squiggly line on the back of the box and then use as many screws as I can to fix it - e.g. things like the grid switches in the garage stick out of the walls and are likely going to take abuse from things knocking them.
There is a very fine line here.
Calling it "no more nails" was a mistake, as there is almost nothing that doesn't require at least a few nails to tack it in place, even if it's decorative trim.
But then, Hilti themselves do chemical anchor kits that rely on a similar principle. So it requires thought about the direction of the loads and what you expect the fixing / chemical to do.
It should really be "glue to help screws". Toolstation's own brand is "glue screws", that works well and is cheaper than the big brand names.
One of my mum's friends (another teacher at her school) recently moved into a newer house and found the ENTIRE toilet & cistern had been fixed with no more nails. Seriously. Not a SINGLE nail, screw or bolt fixing it to the wall. Yeah... the stuff's handy, but damn, an entire toilet!
His wife was about to have a baby as well.
I would say you'd need to be careful with the glue idea and fixing a deck though, as those fixings are there to carry a fair load and the thing it's attached to is reasonably expensive / time consuming (it's not a bit of trim). The glue should be an addition to the plug / bolt, but it should tighten properly as well, whilst the glue is wet. The glue should only be there to fill the gaps the plug doesn't.
{edit} I'd like to a glue shoot out on those cartridges. There are so many versions on the same base and quite big price differences, so I'm thinking it'd be interesting to buy a few different ones then do standardized tests side by side.
