I found help on Reddit for this instead. The long and short of it is, I ended up having to factory reset everything (TV, soundbar, and surround sound speakers) multiple times over the course of a week . . . a huge headache especially since at one point, NO sound was working. I really don't have a straight answer for this because it took so many tries of resetting, unplugging, forgetting devices, reconnecting, etc etc and I honestly can't remember the order anything really went in. I ended up factory resetting my TV twice. After the first time didn't work, I went thru my list of connected devices and made it forget everything (soundbar, speakers, soundbar remote), then factory reset again. After doing that, it finally recognized the soundbar. Then I immediately paired the soundbar remote; this didn't actually work to control the soundbar because when I went into the soundbar UI it kept telling me to "please use my soundbar remote to navigate" even though I already was. BUT something about pairing that remote allowed me to pair the rear speakers to the TV. It's strange because I used this process before and it didn't work, so something about doing this about a thousand times over the past week finally worked. I'm so glad this is over now.
I wish Roku would make their interface a bit more user friendly and their customer service more supportive (or at least give a follow up call when they claim they're going to!) It's hard to find solid directions on the website as well for pairing issues. There's nowhere in the interface that makes it clear whether or not you're pairing to the TV or the soundbar, so it results in a frustrating string of trial and error just hoping that it will connect to the soundbar.