iPhone Lightning Dock Model A1717 not supported by iPhone XS Max
Not to sound flippant, but we (or I) can’t provide you support beyond what Apple’s going to provide so if they consider it “closed” we can’t go beyond that.  However, I can advise you what to do next:


Return it from where you purchased it (it may be defective)
Ask someone at Apple (on-line sales via phone or chat, or in person at the Apple store) what models the Lightning Dock is compatible with.


Ask them if there is a compatibility list.
Ask them if it works with your specific phone

If you get satisfactory answers, purchase it.


If it fails again, open a customer service inquiry and escalate. (If you do the pre-sales question via chat, you’ll have a record).  It may be completely incompatible with your phone and its a perfectly valid, albeit horrible, response/answer.

If you happen to be in store, open the box, hook it up, and make sure it works in font of the sales associate.. Tell him/her exactly what you’re doing and why.  At the very least Apple will be made aware of the deficiency, but most importantly, you’d have saved your money rather than fork over $40USD to a company worth a trillion dollars.