It’s not converging rapidly enough for my liking, so I pause the solve.
Then I look at the N-R Force Residual. The maximum is occuring on the short-crossbar_beams.
It looks like it is this bolt is having problems where it connects the vertex on the cross-beam to the corner solid hole.
So there is some useful information to figure out why convergence is going slow. It looks like that beam is trying to buckle out of a straight line.
I remeshed all the line elements with an element size of 20 mm instead of 5 mm.