Help with invisible decrease

[sapplph]

I'm making a teddy bear (my first project) - I'm half way through the head and now stuck! When I was doing the increase rounds and the maintaining rounds, I always ended up back at the stitch marker in the correct number of stitches. Now I'm doing the invisible decrease rows, I keep ending up short of the stitch marker when I've done the number of stitches in the pattern. I'm counting the decrease stitch as one (not two). I have unpicked and done it again and get the same result. I was one stitch short on a [sc x 5, inv dec, rpt] row and three stitches short on the following [sc x 4, inv dec, rpt] row. Please can someone tell me what I'm doing wrong?!

[Granny Square]

[sc x 5, inv dec] is  worked over 7 stitches (to yield 6)- if this is the direction for the whole round, you have to have a multiple of 7 sts to start with.  If you don't, something went wrong before this round (or the pattern has an error).

And of course it follows if something is wrong on this round, the setup will be wrong for the following rounds....is there a total stitch count given for each round?

Since this is something that will probably not be noticeable if you fudge a bit, and you are ONLY short 1 stitch on the [sc x 5, inv dec, rpt] row, I'd be inclined to omit the last decrease (which will add the 1 stitch back in)- and then count the stitches that you have at that point, and make sure that you have a multiple of 6 stitches so the following round (and hopefully the rest of them) comes out right.