Intellisnap backup failures

So we started migrating vms from vmware cluster 1 with nutanix storage  to pure cluster 2 with purestorage, about 1000 vms: we have intellisnap on both. The diffrnece is we have 50 datastore in nutanix vs 10 on pure, we have configured the job one subclient per lun, the proxies were in nutanix platform but I migrated few to pure, although the controller proxy still in Nutanix, however we seem to be having issues during the first phase when cv proxy requests a vmware snapshot of the vms..it was working all fine however as per the patching process we keep the snapshot on some vms overnight.  My understanding was as long as the networking among proxies does not change atleast the first phase should go smoothly without any load issue irrespective of where the proxies are located either in nutanix or pure cluster...it appears the request to create a vmware snapshot taking too long..we are using the same set of proxies...