Thanks for 5he additional information.
I’m not sure if you and I have different downloads of the pattern, if perhaps it has been corrected and updated since you downloaded it, or if you have made a typo in your original question…
Here is the decrease Row as I see it on my download, back of sweater, page 2
For Sizes 40, 44, 48, 52, 56, and 60" ONLY:
Dec Row 1 (RS): K1, k3tog, knit to last 4 sts, sl 1,
k2tog, psso, k1 – 4 sts dec’d. Rep Dec Row 1 every
RS row X (0, 3, 5, 8, 10, 13) times more, end on WS –
X (77, 73, 73, 69, 69, 65) sts
The row begins with
This is a decrease of 2 stitches. In your question you had “K1, K2tog” a decrease of 1 stitch which would make the decreases uneven.
The row ends with
Sl 1, K2tog, psso, k1
This is a decrease of 2 stitches making it equal to the decreases at the beginning of the row.
The reason for different instruction beg and end of row is making the stitch lean one way or the other for neatness.
The purl row should just be worked as the set pattern, just purl, the lace detailing in the side edges has stopped at this point so it is just stocking stitch (knit right side, purl wrong side) and the purl side should just be an easy run across.
The arm hole bind off stitches at the “shape raglan armholes” just prior to the decrease instructions should not be causing a problem with moving your working yarn or being unable to reach your purl row.
Perhaps you have bound off incorrectly?
Bind off 6 stitches at beg of next 2 rows.
Stitches on left needle for beg of row. Empty right needle, the working needle.
Work 2 stitches.
Pass first stitch over second stitch and off the needle.
One stitch has been bound off.
One stitch remains on working needle and the working yarn is attached to it ready to work the next stitch.
Work 1 stitch. Now 2 stitches on working needle.
Pass first over second and off the needle.
2 stitches have been bound off.
Yarn is attached in correct place on working needle with 1 stitch.
Continue until all 6 bound off.
You will have worked 7 stitches as 1 of them is remaining on the working needle (6 have been brought over and off). Yarn is still in position to work the stitches on the left needle.
These bind offs work for the knit row or the purl row. Work the stitches as you see them, knit the knit row for bind offs, purl the purl row for bind offs.
You have explained clearly by the way.
See what you think about the difference in pattern instructions I’ve posted.
The decreases will be only on the RS, not the purl row.
If it doesn’t make sense please do ask again.
Perhaps you need a video for binding off?
Or a video for the decreases?