Error with Release compilation in Visual Studio 2017

[gmlion]

I get The module/namespace 'MongoDB.Bson.Serialization' from compilation unit 'MongoDB.Bson' did not contain the namespace, module or type 'IBsonSerializationOptions'

when compiling the Release build of my project in VS 2017. The Debug compilation works fine.
A similar error also occurs in F# interactive executing
Serializers.Register()
but I somehow work around it re-opening MongoDB.Bson until it works (usually a second time is enough).
So, executing in F# interactive:
** open MongoDB.Driver open MongoDB.Bson open MongoDB.FSharp Serializers.Register() // this fails open MongoDB.Bson Serializers.Register() // this works **