Take a read of the first post of Please read: make it easier to help you. (Don’t worry about the rest of the thread.)
It’s a lot easier to help if you provide a minimal example of what you tried and what went wrong.
Did set_parameter(model, "NonConvex", 2) take a long time, or the solve itself? Note that non convex quadratics are difficult to solve, and depending on the problem size, it’s not uncommon for it to take a long time.