Thanks everyone for your helpful suggestions.
I have opened up the hub, disassembled completely and there is quite a bit of the factory grease inside and I did not add anything to it. or degrease anything.

Thanks for the link to the manual. The chain shouldn't be too tight since this is on a Brompton and chain tension is maintained by a chain tensioner. I will try going only a quarter turn on the right hand cone and tighten up the left one a bit more to see if that helps. Thanks for the suggestions.