I have the same issue with 2 dvr servers one at my home and the other at our vacation home. This is the work around I do. DVR 1 (home) set to "Remote DVR"= enable on in your settings. At the vacation home (DVR 2) set Remote DVR= Not enabled. Also on the vacation home you have to set Enable Bonjour Discovery to unchecked. The issue you are running into is your remote location sees the local DVR (DVR 2) and will not go to the remote location (DVR 1). Channels uses Bonjour and finds your local DVR and overrides your remote location.
I bought 2 TS4K one is set to the local DVR and the other TS4K is set to the remote location. Then I just switch HDMI ports on the TV to watch either DVR. I turn Enable Bonjour Discovery to uncheck on both DVRs and just use the local ip address for the local DVR since Channels will not discover it. The only thing that changes when I switch between the two homes is enabling "Remote DVR" on just one DVR at a time since Channels only has 1 DNS entry per account. It is a bummer but I hope one day they make this functionality easier to implement.
At one point I had two versions of channels running at the same time on the TS4K (beta and regular version) but this got glitchy and the TS4K are cheap enough and most TVs have more than 1 HDMI port I went with that route.