characteristic of center joint in horizontal x-brace

Ideally, x-braces are modelled as two independent members with no intersection (no node connecting all 4 'parts'). Having a node at the intersection can create instability due to load sharing among all 4 members.

[EDIT]:
I just realised I didn't answer the question. We typically consider them pinned and avoid having them resist moment to simplify calcs and detailing. Basically, have the behaviour as a truss consider purely axial forces and no bending (EA - stiffness)

but then those 4 nodes need to be connected together.

why not a common node ? yes, this would "weld" the joint ... so fully fixed if beams model the cross bracing (or pinned if rods). no?