The sunlight idea makes sense, and that could be the reason thinking back on it. Never occured to me. And thank you for understanding and putting it in words better than I could myself.I'm not sure how much this will help, but I'd like to apologize for the experience you've had in this thread. Rest assured that most threads do not end up this way. I, and many others, try to find ways to open up the discussion without letting my passion (or whatever one wants to call it) spill into what I type. Of course, I'm far from perfect, and I do rely on others here to keep me in check.
To circle back to your original question (which I STRONGLY recommend we all do) of why the cruise control disengaged at 20mph... My initial thought was that MRCC used the radar above a certain speed, then relied on the front camera for lower speeds (similar to the way that SCBS and SBS work). I'm not actually sure if this is the case, but if it is, then any obstruction could cause the front camera to be obstructed and the feature would not function correctly. However, in those cases, the system throws a warning. With no warning, I'm inclined to believe that the radar system (for whatever reason) deemed that there was no car in front of you anymore and let off the brakes. In the fine print, Mazda states that the radar sensor may not always detect a vehicle in front due to it's shape or other factors. I'm thinking that's what happened. The good news is that at that speed, the car's SCBS should kick in to prevent a collision (which wasn't necessary as you had been attentive enough to recognize the situation and apply the brakes as required).
Just as an additional note, the front camera can also be "blinded" by sunlight in rarer cases, triggering a warning even in clear conditions.
Well said. It's perfectly fine to have an opinion and defend it. Trying to impose an opinion on others, saying "I'm right, you're wrong", can very easily carry a crass, demeaning tone, even if that is not the intent. I've been guilty of this (fairly recently too). That tone defeats the purpose of the conversation, and people can become distracted by how they feel about what was written instead of digesting the information and responding with a level head.
As a reminder, the thread was started to ask why MRCC disengaged at 20 mph in this instance. If the off topic discussion continues, I'll have to clean the thread up (which I would prefer not to do as there is a lot of useful information in these posts). Please try to stay on topic everyone, thanks.