I've tried a few things: mainly closing apps that use overlays like afterburner, rivatuner, steam...
It looks like after closing rivatuner I could get past the first screen. After that, epic showed a new pop-up...I believe it was to sync accounts, and to introduce me their own overlay (shift + f3?) After that, I was good to go.
My guess the epic overlay is causing this issue.
Well, let's play.