You actually taught an old dog a new trick.   Amazing   We have used plastic mineral tubs over the years with some success, but they catch enough wind that it eventually fails.

Would you post a better photo of your controller.  We have found the weak spot in the system the controller, but they are exposed to the weather as mounted on back side of the solar panel.  Your brand offers significant difference than the wire nut bar we have used for 20 years.  Lastly having it protected in the box could also help.   Thanks