Methodical, I like it.
On my iphone in Notes I created a note with text to identify the file as being created on the iphone. I copied it to Files and the file name was text.txt. But I already had text.txt files there so it became text 6.txt.
I see text 6.txt on icloud drive in icloud.com with internet explorer.
And I see text 6.txt on icloud drive on my windows 10 laptop.
That looks like success from my iphone to my laptop, right?
On my laptop I created two files, each with names identifying their origin. One was created with file explorer's 'new file' dialog inside of my icloud drive folder and the other was created with the desktop's 'new file' dialog on my desktop and dragged into my icloud drive folder.
Neither file appears in my icloud drive in icloud.com with internet explorer.
Neither file appears in icloud on my iphone.
This failure to update from my laptop to the icloud is the problem that has me stumped.
Thanks.