Is the issue potentially related to (or the same as) this topic?
@carverofchoice mentioned getting someone to look into this, though I don’t know what the status of that is, and I was unable to replicate the user’s issue in the other topic.
In addition to what @Seapup mentioned, something else you could try is forcing your phone onto your router’s 2.4 GHz network by temporarily disabling the router’s 5 GHz radio/SSID (I’m assuming it’s dual-band; maybe also disable 6 GHz if you have that). When I had recent difficulty re-adding an original Plug my ultimate solution was to take the Plug to the same room as the router for setup, and I also disabled 5 GHz on the router and both radios on another wireless access point that I’d recently installed, just so I could make only a single band/access point available for my phone and the Plug.
I don’t know if that will help with your Plug Outdoor, but it’s something I’d try and something I’ve had to resort to in the past for other finicky IoT things that don’t want to connect.