Thank you for sharing that, I think you are having a unique situation with that machine. I know I have installed 18.3 on ten machines personally, and helped others with around 30 more. And another 10 with 20.x. All with absolutely no problems except for one that had this similar issue. It was something with that one machine not allowing Linux to do it’s thing as it should.
No:" complaints about Linux, including Mint, not detecting USB wireless adapters abound, but the only solution (apart from a particular Laptop remedy) I have found requires an Internet connection to fix the problem of no Internet connection.