The Snow Inventory Service gateway seems to have problems scanning. An extract from the log file:

2020-06-10T15:06:19+02:00;trace;;;;RunTask Id=16952 of type 'ActiveDirectoryDiscoveryModule' started

2020-06-10T15:06:19+02:00;trace;task-16952;;;Task faulted.

2020-06-10T15:06:19+02:00;trace;task-16952;;;An unhandled error has occurred in an initialization or run task.

 [System.IO.FileNotFoundException]: Could not load file or assembly 'NetIpHelper.dll' or one of its dependencies. The specified module could not be found.

 at SnowSoftware.Inventory.Discovery2.DestinationHostUnreachableFilter.SelectAsync(IPAddress ipAddress, CancellationToken cancellationToken)

 at SnowSoftware.Inventory.Discovery.ActiveDirectory.ActiveDirectoryCrawler.<ResolveNetworkPartAsync>d__14.MoveNext() in C:\BuildAgent\work\36289f8995c3b254\SnowSoftware.Inventory.Discovery\Inventory.Discovery.ActiveDirectory\ActiveDirectoryCrawler.cs:line 233

Installing Snow Inventory Server 6.5 or higher resolves this issue.