Venue 11 Pro 7130 Charging Problems on Docking Station K10A001

I have multiple 7130 tablets and have noticed variances in the charging patterns when on the tablet docking station K10A001. They are to charge at 45 watts, however they charge at varying rates all around 29 watts. When connected directly  to the AC adapter they charge at the correct 23 watts. I have tried multiple tablets on multiple docks with varying levels of battery life, and still some do not read the 45 watts in diagnostics while charging. Is this a known issue? And is it with the tablet or the docking station?