EVERYTHING is broken after V2.1.1.12

I've been running the RBK53 for a year now without any issues. I've even been recommending it to several people. I've loved it. About a week ago, I started getting mass disconnections of devices across the network. I don't know what changed, perhaps the firmware auto-updated. A few days ago, I updated to v2.1 in hopes it would resolve everything. It did not.

I've spent several, SEVERAL hours this weekend just trying to get this thing to work again. It disconnects every 10-30 minutes. I haven't figured out rhyme or reason. I've cleared the NVRAM on all devices and factory reset them several times. This is a nightmare, and I'm considering returning the product to Costco, buying Eero, and apologizing to everybody I've recommended this product to.