Sadly, I don't think there's a fix for this. The many reports of display, charging and ethernet connectivity issues all point to a problem with the dock, but I still had the same issues after my company replaced the dock so I've pretty much narrowed down my persistent issues to the multi pin port on the Surface. Though an elegant concept, the multi purpose magnetic pin connection always looked like a weak design point to me. I noticed for instance if I bumped the laptop even gently, I'd lose the connection. And relying on such a flimsy connector for so many critical things is a poor engineering choice.
Though they desperately want to be, Msft is not Apple and Msft is not Google - and whenever they try to copy them or compete with them, they seem to fall flat on their face. The Surface is fast becoming the latest evidence of that.