As seen in my post below, I got a visible line at 10DPO that looked pinkish, and was read within the 10 min time limit.
Yesterday when I retested and got a ghostly gray line, I did some googling.
There have been lots of reports of dark gray and even pinkish evaps on the new "6 days sooner" FRERs. Some women say they see a light gray line even before they pee on the stick! I am not sure if this applies to the "5 days sooner" tests, if those are still even around.
So, the typical wisdom of "If you see a line on a FRER you're pregnant, because FRERs don't give evaps" isn't true anymore. Just wanted to save someone the confusion (and disappointment) I had.