And now for an anti-climactic finale…
I took my OT to Elektron support (which turned out to be own the street from where I live - awesome!). They got back to me the next day saying my OT was actually on OS version 1.30 and not 1.30D. They upgraded it to 1.30C, and now the issue is resolved!
Now I could swear I saw the startup screen say 1.30D - but I don’t have a photo to check. Not to mention Elektron tells me that my OT was manufactured before the release of 1.30D 
so maybe I mistook 1.30 for 1.3D and this thread confirmed my belief that I had 1.30D?
I recall seeing a similar issue in one of the release notes, but I was really convinced I was on 1.30D, so I never thought of trying to install 1.30C.
So… sorry for all the trouble 
At least I got to meet awesome and helpful people on here, got a bunch of stickers, and my OT now works!
Thanks for all the help!