Wind on L-sections - open structure

Dear Moderator,

I have lattice tower - mast. When I apply wind on the open structure, distributed load on all sections is correct except for the L-sections (angles). I tried with beta angle, but I can not get the right value if I use 45 or 180 deg. Near correct value I am getting for some beta angle of 12-15 deg.

Please advice.

Regards,