One Drive for Business - junction problem
Directory junction with OneDrive for business folder is impossible due to the way the folder is named on Windows.
Several end users on tenant mytenant.onmicrosoft.com reported an issue with OneDrive for business sync client while trying to use directory junction on their synchronized OneDrive for business folder on windows. Issue is with the name of the synced folder that uses non-standard hyphen. Usually the hyphen on Windows folder names has an ASCII value of 45, but the name of the OneDrive 4B synced folder includes a slightly longer hyphen (–) which prevents creating directory junction.
OneDrive sync client version is 17.3.6386.0412, the latest available build. And the issue can be easily recreated for another user.