Really long story. In short, you have to send all together. Or use the upsert flag in live load -U, --upsertPredicate string run in upsertPredicate mode. the value would be used to store blank nodes as an xid.
The Blank node context isn’t saved “globaly”. So, each new mutation the blank nodes are considered new uids.
You can try also(I think it is easier) xidmapping
"xidmap", "x", "", "Directory to store xid to uid mapping"
It will save the UID context to a path called x and you have to use this flag in every load.