Yea, budget strobes. Two theories here.

1. Buy the ones made for your camera by the camera maker. Not budget, but they always work.

2. Buy non-OEMs that get good reviews, save some bucks and take your chances. They should specifically state that they will work with your body's remoted flash function.

When I dropped my #2 flash, a Nikon 800, I had to pick something up quick to use with my 900. I drifted into a local shop and bought a ProMaster built for Nikon commander mode, and it worked great at about 30 percent of what I paid for the 900. Guide number was just not quite as high as the 900, but fared well into an umbrella in a multi-strobe set up. Unfortunately, I think ProMaster is out of business, but there are lots of knock-offs out there, and I'm sure someone else on this thread will have some good experience.