Sometimes on blender startup it is waiting for return key on console before loading

I have this since a while:
1 out of 10 times I start blender it wont start properly - the window is white and the console window title changes to ‘Select Blender’ and just sits there.
Once I press ‘Enter’ it says read prefs etc. and loads up instantly.

I do have several versions running (eg. 2.83 and 2.82).
A few addons: luxcore, qblocker but I don’t suspect them

I have not found any pattern why and when this happens and also google did not help me… anyone has similar experiences?