Based on what David has shared, and the horror stories I have read on the internet, if you haven't opened the box yet, I'd sell it or return it if you can.
There is a few things going on there, to be honest. I have had it too long, and while it hasn't been used on a rig yet it has been opened, and the battery was charged for storage. The second issue is it is the last gift my wife of 26 years purchased for me, and she believed at the time she was buying me the latest greatest. Three weeks later she passed, so regardless of if it works or not, I will never be getting rid of that radio. Besides, I never like to sell things with issues, without telling the person who is buying it what is going on. At that point, they either wouldn't want to buy it, or would want to buy it for pennies on the dollar, and I wouldn't do that. That is precisely why I have never sold my Cayman Pro RTR, it is so incredibly fragile, and the moment I tell that to a prospective buyer, they'd likely only want to pay a price I would be unwilling to accept.
But, there is good news on that front, I recently received the new front axle from Furitek, and it is all aluminum construction, a lot more heavy duty than the originals are. As soon as they make the rear axles available for purchase, I plan on buying one of those. At $90 for the front axle, these things had better be tough. If I can find some stronger driveshafts for this rig, then I believe all of it's weaknesses will have been addressed, and I will be driving the heck out of it around the house. Making crawler courses with household items, and having a blast!
Now that we mention it, maybe you can help me, when measuring a driveshaft, I assume you'd measure it from u-joint to u-joint, while it is connected to the truck, am I right on this? It is the only thing that makes sense to me. With these new axles, I may simply begin looking for some driveshafts with will fit, elsewhere, since Furitek is always out of stock on their new metal ones, and the original plastic ones snap super easy.