Hi,
The proxy sensors unfortunately do get impacted and as they are needed to control the movement to the alternative directional change, a loose or impacted one should always be checked for. When a truck ships new a spare one is provided in the cabin.
If you still need support, you can complete a quick technical support form at the bottom of the main combilift.com web site or direct link https://warranty.combilift.net/technical-support-form/. The form only asks for the minimal info so the team can quickly help you. There is no login required and no charge for this support.
Combilift has Technical support technicians across the world including in NC at the North America Headquarters, that can help.
You can also request access to our knowledgebase where you will find more information available. Hope you get sorted.

Check proximity switches on steering. There should be two switches at each wheel. Make sure the gap between switches and pickup tab isn't more than.25 inches. The factory doesn't do a very good job setting them up.

Generally there are issues with the sensors on the rear wheel. Have lots of problems with worn turntable bearings and the steering ram trunions not allowing the wheel to come around enough.