The following message was posted by Himsa:

The Microsoft Spring Update 1803 for Windows 10 was released on April 30, 2018. This Microsoft update breaks the Bluetooth communication between the computer and NOAHlink; therefore, you may be unable to pair or discover the NOAHlink in NOAHlink Properties.

If you have the option, decline the Windows Spring update for now.

If the update has already been installed, and the Noahlink is required, the only fix at present is to roll back the Windows update. You will find the option to rollback at Settings, Update and Security, Recovery. Select ‘Go back to the previous version of Windows 10’.

HIMSA is investigating this problem and an update or solution for NOAHlink will be delivered as soon as possible.

https://www.himsa.com/en-us/support/noahlinkknowledgebase/noahlinktroubleshooting/noahlinkandthemicrosoftspringupdate1803forwindows10.aspx