Need help getting Buttkicker Gamer 2 to shake

So last night my Buttkicker Gamer 2 was delivered, and I am having trouble getting it to shake with SimHub.

In SimHub, I've selected my motherboard speaker output, listed as Realtek Speakers.  I have the 3.5mm headphone jack to the Buttkicker Gamer 2's included amp connected to my motherboard's center/sub output.

I have my Windows sound output to Voicemeeter VAIO.

I have several outputs linked to Voicemeeter VAIO, which are:

• My computer speakers using my new soundcard (ASUS XONAR SE 5.1 Channel 192kHz/24-bit Hi-Res 116dB SNR PCIe Gaming Sound Card)
• My TV thru HDMI
• My desk headphone external DAC (connected to motherboard via USB)
• My Valve Index HMD headphones.

All my audio works as intended, and when I test my output in SimHub I see the soundbars peak green but my Buttkicker doesn't respond at all.

I've tried:

1. Using the Realtek software for motherboard's audio output to disable all speaker outputs except for the center/sub output.
2. Using the Realtek software for motherboard's audio output from surround to stereo, and to mono.
3. Uninstalling and reinstalling my motherboard's Realtek audio driver.
4. Trying every combination of button settings on the Buttkicker's included amp.
5. Adding my motherboard's Realtek Speakers (that is fed to the BK amp) to Voicemeeter as an output.  I did this even though I know SimHub uses it for telemetry and does not use the PC's audio.
6. Removing my desk headphone external DAC (USB) as one of Voicemeeter's outputs.  Connecting my BK's amp's 3.5mm jack to my DAC, then selecting that as SimHub's output.  Same result.

What I haven't tried that I thought of this morning is to test to see if my center/sub jack output was changed with Realtek software before I installed the new soundcard (when I was using that for my computer speakers previously).  So I haven't moved the Buttkicker's amp's 3.5mm jack to any other 3.5mm jack output at my motherboard.

But I would figure SimHub would declare a "Connection Error" for the selected Reaktek Speaker output if the 3.5mm headphone jack was plugged into the incorrect motherboard 3.5mm output, like I've seen while troubleshooting before.

Not sure if that makes sense.

But I am beginning to wonder if I HAVE to use the new soundcard for the Buttkicker's amp?  I wanted to use that for my actual audio, figuring that's a better quality sound than my motherboard's audio.

Any ideas at all would be very much appreciated!  I was really wracking my brain and getting very frustrated.  I am sorry if I am missing any information, but by the time I have done all this it was getting pretty late last night, and I'm writing this in the morning at work from memory.