While towing my 2014 Equinox a couple months ago through an interstate construction zone about 50-55 mph the steering on the tow went unstable and started violently swinging from hard left to hard right. Stopping was the only way to get out of this. After stopping and checking for damage, none apparent, it towed fine the rest of the way. The tow bar was level and tires at correct pressure. I had the alignment checked at a Chevy dealer and 3 of the wheels were out, don't know if this bad alignment was before the incident or damage from the instability. I have towed this car over 15,000 miles. It has towed fine the rest of the year. Wondering if anyone has heard of this before and what caused it?