If the dock or the Deck detects your cable being bad, charging will slow down automatically. Lying, fake cables can cause this problem; alternatively, lying, fake cables can also cause electrical fires when the plastic melts or damage to your equipment.

If you have another device available, try plugging in something like a phone or a tablet or a laptop that also supports USB-C charging to see if it’s just the Deck or if something else is wrong. If everything but the Deck fast charges, it’s possible that there’s something wrong with the Deck (filth in the port?), the charger, or the dock (lying spec sheet? knockoff? scam?).

The deck charges with about 45W max, if your outlet isn’t producing that I doubt you’ll be able to do anything with them. That’s less than an incandescent light bulb!