I would not mess with that mag box much more, seems you've done all that can be done. I would have to say that if nothing worked so far, it probably won't get any better.
If you have another router in house, try using that other in place of the one you using now.
It's a long shot but just maybe
If you have another router in house, try using that other in place of the one you using now.
It's a long shot but just maybe