no, not a "fresh" install. only fresh since the 19 release and been updated/upgraded since. the computer i was on in my last post above was a fresh install of mint 19.1 and then immediately upgraded to 19.2 though.
will have to do this tomorrow as not at home today. i did post a topic about this on the mint forums and, so far, 1 other person says they get the same thing happening.
this is that person's reply:
"It's the same here. Download tests work fine but the "old version" upload test does also work. There's an option toward the bottom right.I did notice that in both site versions, the upload data amount isn't populated by default, but entering the desired amount in the new version still resulted in being bounced back to the home page. Necessary scripts allowed but will also see if disabling Ublock Origin for that site makes any difference"