From their website, it says about the difference between the v3 and the v3 Pro:
“A stronger Wi-Fi connection with 2 antennas.”
My experience is that the Pro version has a much weaker Wi-Fi connection. I replaced two v3 cameras with v3 Pros, at the exact same location, and they struggle mightily to maintain a connection with my router. So I finally threw up my hands in frustration and put back the original non-Pro cameras and they continue to have a strong network connection.
Mine works as good or better than the v3. Keep in mind the pro is 2k, so the bandwidth required for it to operate is increased. If your router is struggling, or your internet connection is limited, it could be causing issue.
His testing and graph showed the Pro better than the V3 out until 68 ft but both below the V2. Then the pro is only slightly below the V3 the rest of the way out in distance until they both become unusable. The V2 drops out quick with distance though and at 50-60 feet, the Pro was the strongest signal of all three cameras.
Okay I switched to the 2 amp one and the problem still exists, but to a lesser degree, I think.
BTW, there are many people on this forum who are reporting this exact same problem in another thread. It seems to be related to night/day usage as well. My Pros stream just fine during the night, or at very low light, but when the sun comes out they crap out.