For much of the 2016 - 2017 model years on almost all RVs with LCI suspension and hubs, there was an excessively high rate of grease seal failures resulting in grease on the brake shoes and drum surfaces. This resulted in braking failure, but I'm not sure it would cause locking up (just the opposite!). As midnightsadie said, you won't know what's going on until you pull the hubs and look. It's a safety must-do before you tow it again, though. Lippert has been honoring warranty issues on the brakes - often through your RV dealer and/or manufacturer.
Rob
Rob
