Sock Pattern Confusion

I just started this new sock pattern tonight (I’ve only knit one other very basic one before) but the directions for the heel are stumping me. I hope I’m not crazy. I’m following Bernat’s Basic Socks pattern (s3.amazonaws.com/spinrite/pdf/WEB-BERNAT-SOX-K-BasicSocks-ENG.pdf) and for setting up the heel stitches it says:

Arrange heel sts: 1st needle: K10. Slip
next 5 sts onto beg of 2nd needle.
2nd needle: Knit.
3rd needle: Slip first 5 sts onto end of 2nd
needle. K15. Divide 30 sts of 2nd needle
onto 2 needles and leave for instep.

Simple enough at first glance. But we start with 60 stitches divided 20-20-20 across 3 needles and following these directions I feel like I’d be missing 10 stitches somewhere? The pattern is also not clear on what needle we’ll be developing the heel from or how many we should have left after this step. Please help!!

Welcome!
There’s a mistake in this section. Knit 15sts on first needle, slip last 5sts onto beg of 2nd needle. Knit 25sts on 2nd needle. Slip first 5sts of 3rd needle onto 2nd needle. Knit these 5sts. Knit 15sts on 3rd needle. You’re now back to the marker.
You’ll end up with needle 1, 15sts; needle 2, 30 sts (instep); needle 3, 15sts. Needles 1 and 3 are the heel.
You can divide the sts on needle 2 onto 2 needles now or just cap the needle and hold those sts till the heel is finished.

Thank you so much for the help! The next bit of the instructions are:

Make heel: 1st row: (WS). Sl1P. Purl to
end of row.
2nd row: *Sl1. K1. Rep from * to end of
row.
Rep last 2 rows for 2½” [6 cm], ending on
a WS row.

Considering how the instructions only mention to go through the 3rd needle and I ended the previous instructions at the marker (which is in the middle of the 1st and 3rd needle and the middle of the heel row) should I knit through to the end of the 1st needle and then begin making the heel on the WS?

Yes, that’s it exactly. You’re working yarn is between needles 3 and 1, so knit to the end of needle 1, turn and work back on 1 and 3. The first full heel row will be row 1 on the WS.