Hi,
The problem here is that the Measure you are using in the form integrals are not based on the same domain (=mesh) as the trial and/or test functions involved :
For instance, in inner(lam_Rh, u)* ds_R : lam_Rh is in V_lam_LR based on mesh_LR, u is in V_u based on mesh but the measure ds_R is defined from domain = mesh_R.
Your measure should be based on mesh_LR instead, possibly with some subdomain_data.
But I guess you’ve already figured that out, considering your other post here.