(...) is it safe to assume that this authentication process cannot be made to synchronize with just one device?.. cus scanning out the code on the app would definitely need two devices..
You
can do everything from a single device if you want (for example, most of the testing I did during development took place by ignoring the QR code and just copy-pasting the shared secret into KeePassXC).
I mean, single-device 2FA will make some people wag their finger at you, but I'd
personally feel pretty comfortable keeping my shared secret in something like KeePassXC on the same device that I log in from. I'm a little biased though, because I
hate using my phone (if I could yeet the contemptible thing into the fuggin' sun, I would; if it wasn't for my wife calmly preaching pragmatism, and trying to keep me on the reservation, so to speak, I probably wouldn't even own one).
(...) Am I the only one any help will be appreciated.
I'm sorry for the month-late response...
I think that what likely happened there is that you mistyped your OTP and then got spooked by the badly-worded error message. That error message has now been improved.
There's a URL on the icon in the 2FA - it leads to a parked domain advertisement. Is this deliberate, or a blunder?
You mean the QR code? The QR code contains a specially-crafted URI that's meant for convenient importing of your 2FA secret/settings into a TOTP-compatible authenticator application. It's not meant to be
navigated to.
It's worth pointing out that scanning the QR code is optional: all of the info you need to
manually import your 2FA secret (and related settings) into any TOTP-compatible application can be obtained from the account settings page. (More detailed settings, which are rarely needed because they correspond to widely-compatible default values, are visible when hovering over the "Shared secret (Base32)" field label.)