You may be interested to know that Nitrokey Fido U2F fails to login starting with Chrome 73 (now beta). LED is not flashing and the request eventually reaches a timeout.
This is due to a new feature they call WebAuthenticationProxyCryptotoken. One can login only if chrome is run with
See https://bugs.chromium.org/p/chromium/issues/detail?id=935131 for more info.