Several of our bikes have fenders and racks mounted, and when we were shopping for hitch-mount bike racks there were fewer options that officially supported carrying bikes with fenders. We ended up with the Thule EasyFold XT2. It isn't cheap, it isn't light, it isn't as quick and easy to attach / remove bikes, but it carries any of our bikes very securely.
https://www.thule.com/en-us/bike-rac...-xt-2-_-903202