Got the lockout message again today using IE and chrome on Win10, except the first message said 21 minutes, instead of 30. I can log in fine with iOs. I logged in a couple of days ago without getting locked out, so not sure what the 21 minutes is today.
Everything else works fine, shrug. Maybe something to do with a recent windows update? because it doesnt seem to happen on any other os/device. Out of interest, does your wife's Win10 have the same updates installed as your one?
EDIT: I just tried safari on macOS and also getting locked out, so it isn't limited to Win10. Safari on iOs still logs in fine even now, however.