That's very strange, unless the issue is something else, such as USB IC (U2). Hope you have a valid back up on your computer or iCloud. If not, back up ASAP, one way or the other.
Then my advice would be to take it to a reputed/trusted repair shop and have them look at it, to save you from buying more parts for testing.
Either the replacement charging dock is defective. That happens a lot.
Or you installed it wrong.
Or the issue is something else completely, such as your charging and data sync circuit (U2 USB IC as we commonly call it) being defective. The part about charging at an angle puzzles me, otherwise your issue as described (where replacing the charging dock doesn't solve it) indicates charging circuit slowly giving away in my opinion.