When playing ARK; PulseAudio cannot change playback device

I've got a weird issue that requires someone with more Pulse Audio experience than I have.

Whenever I launch "Ark: Survival Evolved" through Steam, on KUbuntu 16.04, I have no sound. I've checked Pulse and it shows that the audio is being piped to the system sound device; I attempt to change it to my USB external sound card (which works for everything else), and it refuses to change. The menu closes, and it's still defaulting to "Built-In Analog Stereo", which isn't hooked up to anything.

I did not have this issue on KUbuntu 14.04; and this is a fresh install on a different hard drive. No configuration files were copied over, just music, pictures, videos, and documents. I've used Pulse for a long time (musician), and with a lot of different equipment; I've never had this issue with anything before and I've done some weird stuff.

The current "solution" is either to attach my speakers to my default audio output--which is not easy due to space limitations--or to play it on another OS, which is just obnoxious.

Is there a way to set it up to pipe to a specific output before starting the program? Given that this is early access, I'm guessing that it just isn't "getting" Pulse Audio when it attempts to pipe; but I could be wrong.

Thanks for any help you can give me. This is my chill-out game. It isn't worth a reboot.

UPDATE: I discovered that most of this can be resolved by copying default.pa from /etc/pulse to ~/.config/pulse ; special thanks to Nebuzaradan at https://unix.stackexchange.com/questions/293399/how-to-set-hdmi-sound-output-as-default-on-ubuntu-16-04 . This forces every program, including the fidgety ones like the above, to default to the settings established in it. Probable bug?

ADDITIONAL UPDATE: My method seems to work, but occasionally requires me to kill and restart pulseaudio; which is a move from highly-inconvenient to a-lot-less-inconvenient-but-not-quite-perfect. I'm still not sure what's going on with the default file; but will update this for others who have the same question as I figure it all out.