Hello, I'm not able to connect to my Bela Salt from my Mac. The BELABOOT storage device shows up on my desktop and I can see Bela in my USB Device Tree:


But it does not advertise itself as a network interface. There is no option to add a BeagleBone Black interface. I've plugged it into via ethernet to my router as well and it does not show up in the list of connected devices. I've also tried connecting it via ethernet directly to my computer, I tried both a USB ethernet adapter and thunderbolt ethernet adapter. In both cases it just says that it has a self-assigned IP address and I'm not able to connect.
I've downloaded the latest image and flashed an SD card, but I can't get it to boot from the SD card. I tried holding down the user button while booting, but it didn't appear to make any difference. If an SD card is in, I get no led activity near the reset and power buttons. If the SD card is out I get a steady blink on the led closest to the power button and a repeating double-blink on the one nearest the reset button. http://bela.local and 192.168.7.2 are never accessible, never pinging, unable to ssh.
I'm on macOS 10.14.4 and this is actually the first time I've even powered it on and I'm the first owner. What next steps can I take to troubleshoot this?