Can not resolve "Error in routine cdiaghg (542): S matrix not positive definite" error.

Hello, I've been having difficulties running a system with noncollinear magnetism using a fully relativistic ECP and hybrid DFT functional. While I can achieve convergence for non-hybrid DFT, the code crashes for hybrids with the mentioned error in the title. I checked for some possible culprits:

  1. I checked that the geometry is OK since I can run hybrids in the same geometry using a scalar relativistic ECP in the ferromagnetic phase (FM).
  2. I checked for ghost states in my ECP and there appears to be non according to the OPIUM code. I also tried using another fully relativistic ECP and see the same error.

I then tried to modify my input parameters as following to resolve the error with no success:

  1. Increasing mixing_ndim.
  2. Using different mixing_mode.
  3. Decreasing mixing_beta.
  4. Changing the smearing scheme.
  5. Using larger pw-cutoff (400 Ry).
  6. Using a different k-mesh.
  7. Using occupations = 'fixed'.

To give more info, I am trying to see the contribution of spin-orbit effects on the gap of this system. Particularly, I ran the FM phase in the scalar relativistic case, and therefore starting the magnetization in the noncollinear case from FM magnetization. I should note that nosym = .true. flag is needed for me to convert the orbitals for subsequent QMC calculations. Any suggestions will be quite helpful, and the input/output files are attached below.

Version used: v.6.4.1

Machine: Andes/OLCF

qe_sorep.zip