NYETEI Team
5 months ago
From your description, it sounds like the preset may have been selected but not assigned to the object before generating the collision shapes. Here are the quick steps that should solve it:
Select your mesh or meshes
Select the preset you want to use
Press Shift + Q to open the pie menu
Choose Assign Preset
Generate the collision shapes again
For a concave mesh like a torus, this should produce multiple convex shapes rather than one single convex shape.