Latest firmware for your device is TL-SG108E(UN)_V6.6_1.0.0 Build 20220930, September 2022. It's up on the firmware link that Somnus provided.

The switch has loop prevention built-in, so loops probably weren't the issue. The OPNsense router, on the other hand, was configured to communicate via LACP LAG to the Switch over 3 ports, so I...

Figured it out... To anyone else that runs into this issue...don't configure LAG LACP until the switch is fully adopted. Once I disabled LACP LAGG on the switch and router, the adoption FINALLY...

@RamtinR So how can the switch be configured within the controller if it's resetting the IP to 192.168.0.1? Why would the adoption place the switch on a network it can't communicate with? I'm fine...

That didn't work...Switch still reverting to 192.168.0.1 during the Omada adoption process...

The only relevant post I've found so far seems to be this one: https://community.tp-link.com/en/business/forum/topic/583776 I had my SSH port set to a non-standard port when I tried to adopt this...