I was getting the same results you were, pattern was not there or if it was,
it was really collapsed. Here is what I found made it work for me, and why I think it wasn't working my first try.
I'm using the free Treads mitt pattern from Ravelry. When I was doing the linen stitch for some reason I thought the 4 RND pattern ended with a purl row and began with a purl row, thus I think I was unconsciously putting an extra purl row between each 4 round set. Also I wasn't sure that I had alternated slipping or purling the first stitch of the slip stitch rounds (rounds 2 and 4). So, after rereading the stitch discription, I made sure I did each RND absolutely as stated: 1 RND, purl; 2nd, *sl1pw wyb, p1, *rep; 3 RND, purl; 4 RND, *purl1, sl1pw wyb, *rpt. When I kept repeating these 4 rows exactly, voila!!! The pattern shows up big time.
So, ending the 4 round pattern with a slip stitch round, starting the next 4 rounds with a purl round, and making sure to alternate the first stitch of slip stitch rounds fixed my problem. Maybe the same will work for you. One can hope.