Users have reported that there are serious reliability issues with Microsoft Windows updates KB4480970 and KB4480963 which rolled out to users on Jan 8th 2019 (see links below). If you can't connect to your machine and are being repeatedly prompted for your Windows Credentials, then you may be affected by the bad update.
Updated Jan 14th: To fix this please install Microsoft's KB4487345 follow-up update on the affected machine from here: https://www.catalog.update.microsoft.com/Search.aspx?q=KB4487345 . After you install the update, reboot the machine and you should be able to connect properly from that point onwards.
Updated Jan 20th: If you need to connect to an affected machine try disabling Jump's NLA mode:
- On iOS: Tap the 'i' next to your computer's name and then click Edit. Then turn on the NLA option in the Advanced section.
- On Mac: Right click your connection icon and then click Edit. In the Advanced section make sure Network Level Authentication is enabled.
- On Android: Tap the blue button next to your computer's name and turn off the NLA option.
More information about the bad update: