Cubase 9.5 export problem

Today I came across an issue with Cubase 9.5. On a large 225 track mix it would not export a 44.1 24 bit mix offline. It just hung. Using Cubase 9 no problem same file same export settings. Tried both 64 and 32 bit processing with 9.5 but still no success. Finally tried 64bit processing with real time export and voila it exported perfectly. Anyone have any ideas why it won’t export offline but works using realtime?

Some times the display is not updated, it renders but looks frozen.
Next time try giving it 5 or 10 minutes, it might complete the rendering.
I have encountered this issue multiple times, but the cause have been different.
A buggy VSTi that only worked reliable in real time.
A ASIO driver also set to allow a few WDM channels being used by win10.
Those are the ones I have had lately.