Why ASCS is reported as 'not running' when ERS groups moves out of node where also ASCS group was running?

Issue

Running ASCS and ERS instances via separate SAPInstance reosurces in 2 resource groups causes the ASCS to be stopped when ERS group moves out of the node that was running both ASCS and ERS resource group.

## Before move
   Resource Group: ASCS_group
       fs_RH1_ASCS        (ocf::heartbeat:Filesystem):    Started node-1
       nc_RH1_ASCS        (ocf::heartbeat:anything):      Started node-1
       vip_RH1_ASCS       (ocf::heartbeat:IPaddr2):       Started node-1
       rsc_sap_RH1_ASCS00 (ocf::heartbeat:SAPInstance):   Started node-1
   Resource Group: ERS_group
       fs_RH1_ERS (ocf::heartbeat:Filesystem):    Started node-1
       nc_RH1_ERS (ocf::heartbeat:anything):      Started node-1
       vip_RH1_ERS        (ocf::heartbeat:IPaddr2):       Started node-1
       rsc_sap_RH1_ERS10  (ocf::heartbeat:SAPInstance):   Started node-1 
## After move
   Resource Group: ASCS_group
       fs_RH1_ASCS        (ocf::heartbeat:Filesystem):    Started node-1
       nc_RH1_ASCS        (ocf::heartbeat:anything):      Started node-1
       vip_RH1_ASCS       (ocf::heartbeat:IPaddr2):       Started node-1
       rsc_sap_RH1_ASCS00 (ocf::heartbeat:SAPInstance):   Started node-1
   Resource Group: ERS_group
       fs_RH1_ERS (ocf::heartbeat:Filesystem):    Started node-2
       nc_RH1_ERS (ocf::heartbeat:anything):      Started node-2
       vip_RH1_ERS        (ocf::heartbeat:IPaddr2):       Started node-2
       rsc_sap_RH1_ERS10  (ocf::heartbeat:SAPInstance):   Started node-2 
Failed actions:
* rsc_sap_RH1_ASCS00_monitor_120 on node-1 'not running' (7)

Cluster logs are reports that during move of ERS the ASCS processed were stopped because they were accessing the ERS directories.

Filesystem(rh1_fs_ers10)[27942]:    INFO: Running stop for nfs-storage:ERS10 on /usr/sap/RH1/ERS10 
Filesystem(rh1_fs_ers10)[27942]:    INFO: Trying to unmount /usr/sap/RH1/ERS10 
Filesystem(rh1_fs_ers10)[27942]:    ERROR: Couldn't unmount /usr/sap/RH1/ERS10; trying cleanup with TERM 
Filesystem(rh1_fs_ers10)[27942]:    INFO: sending signal TERM to: rh1adm   14232     1  0 02:42 ?        Ssl    0:00 /usr/sap/RH1/ERS10/exe/sapstartsrv pf=/sapmnt/RH1/profile/RH1_ERS10_rh1-ers -D -u rh1adm    
Filesystem(rh1_fs_ers10)[27942]:    INFO: sending signal TERM to: rh1adm   21604     1  0 02:51 ?        Ssl    0:00 /usr/sap/RH1/ASCS00/exe/sapstartsrv pf=/sapmnt/RH1/profile/RH1_ASCS00_rh1-ascs -D -u rh1adm 
Filesystem(rh1_fs_ers10)[27942]:    INFO: sending signal TERM to: rh1adm   21786     1  0 02:51 ?        Ss     0:00 sapstart pf=/sapmnt/RH1/profile/RH1_ASCS00_rh1-ascs 
Filesystem(rh1_fs_ers10)[27942]:    INFO: sending signal TERM to: rh1adm   21806 21786  0 02:51 ?        Ss     0:00 ms.sapRH1_ASCS00 pf=/usr/sap/RH1/SYS/profile/RH1_ASCS00_rh1-ascs 
Filesystem(rh1_fs_ers10)[27942]:    INFO: sending signal TERM to: rh1adm   21810 21786  0 02:51 ?        Ssl    0:00 en.sapRH1_ASCS00 pf=/usr/sap/RH1/SYS/profile/RH1_ASCS00_rh1-ascs 
Filesystem(rh1_fs_ers10)[27942]:    INFO: unmounted /usr/sap/RH1/ERS10 successfully 
[12867] node-1       lrmd:   notice: operation_finished:     rh1_fs_ers10_stop_0:27942:stderr [ umount.nfs4: /usr/sap/RH1/ERS10: device is busy ]