VB6’s concept of OOP was different. Sure the same keywords are found: Module, Sub, etc but it was rewritten to run on IL/NET VM. Fundamentally changing it from a COM compatible language to a .Net framework compatible one.
VB6's concept of OOP was simple enough it could have been translated into .NET and .NET is broadly compatible with COM. I'm certain Microsoft could have made it work. They really needed to consider VB6 as a backwards compatibility target instead of building VB.NET as a modern replacement. VB.NET really has no reason to exist; it's not compatible enough with VB6 but then also includes a bunch of VB6's weirdness.