Problems in sharing control are usually indicated by abends in the IGWXSxxx modules. Or by incorrect output of the SHCDS command.
The following is an example job for obtaining a DFSMSdss dump of the sharing control active data set. Change the OUT and DUMP statements as appropriate.
//DMPSHCDS JOB ...
//* JOB TO DSS DUMP SHARING CONTROL ACTIVE DATA SET. CHANGE JOB
//* AND OUT DD STATEMENTS AS APPROPRIATE.
//DSSDMP EXEC PGM=ADRDSSU,REGION=4M
//SYSPRINT DD SYSOUT=H
//OUT DD DSN=DUMP.SHCDS,DISP=(,KEEP),UNIT=CART,
// VOL=SER=CART01,LABEL=(1,SL)
//SYSIN DD *
DUMP DS(INCLUDE(SYS1.DFPSHCDS.ACTIVE.SPLXPK)) SHARE -
TOLERATE(ENQFAILURE) -
OUTDD(OUT)