Hello guys, I have been having the same issue and tried to find the solution without any success. Fortunately, I believe I have recently found the solution to this issue (I don't know if some has already mentioned it above)
The problem is, your samsung account might be disconnected in the background, without any notice. I don't know why, but the app doesn't tell you your account is actually disconnected (in fact, some account functions still work fine so it is not completely disconnected, I don't know if this makes sense)
The solution when you have this remote connection issue is go try buying any of the apps through your Samsung Gear app. If you do that, the app will tell you that you are actually disconnected from Samsung account and cannot buy anything. Simply login to your account again, and cancel your purchase. Now you are connected to the account again, and your remote connection will be working fine.
This solution worked perfectly in my situation, and hopefully solve your issues too. Now I do not factory-reset my watch everytime I have remote connection issue. I simply go re-login to my Samsung account. Thanks.