Syzygy sub app not responding

Hello Audiogon world.  I just updated the iOS on my iPhone 8 and now my Syzygy control app tries to load, but I only get a black screen. The phone's Bluetooth is on, and I re-downloaded the app a couple of times. I unplugged the sub, hit the reset button, etc. No dice.  I sent an email to the folks at Syzygy. Have any Syzygy owners experienced this?  I have the SLF 850 model by the way (which I love).  Thanks!