running interactive OK but PBS SIGSEV

Hi all,

this is a bit of a strange question but I have tried almost everything that comes to mind to no avail:

I have compiled QE 6.4.1 and EPW 5.1.0

[code:d10dzdtq] Program EPW v.5.1.0 starts on 14Aug2019 at 5:12:43

 This program is part of the open-source Quantum ESPRESSO suite
 for quantum simulation of materials; please cite
     "P. Giannozzi et al., J. Phys.:Condens. Matter 21 395502 (2009);
     "P. Giannozzi et al., J. Phys.:Condens. Matter 29 465901 (2017);
      URL http://www.quantum-espresso.org", 
 in publications or presentations arising from this work. More details at
 http://www.quantum-espresso.org/quote

 Parallel version (MPI), running on    32 processors

[/code:d10dzdtq]

I can run qe interactively or from my PBS pro schedule without problem but I can only run EPW interactively; If I try to run it via qsub (even though it runs on the same physical machine) it crashes with the following

[code:d10dzdtq]forrtl: severe (174): SIGSEGV, segmentation fault occurred
Image PC Routine Line Source
epw.x 0000000000EF10C3 Unknown Unknown Unknown
libpthread-2.17.s 00007FF028350370 Unknown Unknown Unknown
epw.x 00000000004114E3 elphon_shuffle_wr 193 elphon_shuffle_wrap.f90
epw.x 000000000040BE4B MAIN__ 150 epw.f90
epw.x 000000000040B1E2 Unknown Unknown Unknown
libc-2.17.so 00007FF027C9FB35 __libc_start_main Unknown Unknown
epw.x 000000000040B0E9 Unknown Unknown Unknown[/code:d10dzdtq]

this happens directly after the wannier90 output is echoed in the epw output; during the run the memory consumption is about 12 GB of 180 GB;

I have checked that the executable and mpirun are the same in both cases

[code:d10dzdtq]/usr/local/qe-6.4.1-test_compiler/q-e/bin/pw.x
/usr/local/intel/compilers_and_libraries_2019.0.117/linux/mpi/intel64/bin/mpiru[/code:d10dzdtq]

I wonder if anyone else has had a problem like this - any hint would be appreciated!

Best,
Chris