r2SCAN CUTOFF convergence

[Max H]

Dear all,

I am trying to implement the r2SCAN functional for my calculations and struggle to converge the values for the CUTOFF and REL_CUTOFF. As some have observed earlier, it is difficult to get the accuracy below 10^-3 Hartree and I encounter the same challenge for my system (Cu, O, C and H).
I tried the following steps to resolve this issue, albeit without success:

1. Raise CUTOFF systematically up to 3000 at REL_CUTOFF 100 (same at 200).
2. Apply smoothing in the XC_GRID section, e.g. XC_DERIV SPLINE3_SMOOTH and XC_SMOOTH_RHO NN10 (and NN50).
3. Use the GPAW method instead of GPW (as some noted that CUTOFF convergence is easier).

I have been using the DZVP-MOLOPT-SCAN-GTH basis sets and the GTH-SCAN pseudopotentials for the tests with GPW and the 6-31G* basis set for GPAW.
The input files are attached (although I left out the exact structures, as the problem should be quite general).

I would appreciate your suggestions to solve this issue or point it out if I made an obvious mistake.

All the best,
Max