GPS marker is offset half the implement length

Just installed GPS non RTK system and unable to get to work properly. When traveling back opposite direction on on original line the paint marker is offset half the implement length [60ft implement and offset 30ft], but if I follow line in original direction it has zero offset. Double checked offset setting and is 0. Not sure if Im missing something simple or if it could be a issue with antenna. Thanks for everyone’s help

I would re check all measurements.

What type of non RTK corrections are you using? What GPS chip are you using?

using uBlox F9P SSR GNSS receiver + antenna.

Do you have u center installed?

With boundaries you can choose which side of implement. !!make sure you are using AB line not boundary by mistake!!

There is a hidden setting for gap and over lap. It is on the page with the clock icon. I have missed that a time or two.

Without RTK I was having 24” lime jumps randomly, but not 30’