Sync gateway - revision id capture

Hi Team,
we have 3 sync-gw setup and it was front ended by the Load balancer when we try to hit the SYNC GW rest end point.
Question is,
when I try to look up the actual document revisions, some of the revisions are available from SYNC-GW Rest GET document API but some times it is not available( all revisions are happened for the same days).

Below is our SYNC-GW configuration,
“allow_conflicts”: false,
“revs_limit”: 10,
“delta_sync”: {
“enabled”: true
},
“cache”: {
“channel_cache”: {
“max_number”: 5000000,
“max_length”: 1500,
“min_length”: 1500
},
“rev_cache”: {
“size”: 200000
}
}
},

Sync Gateway only guarantees that the current revision and any unresolved conflicting revisions are available.

Other revisions may be returned if they are still resident in the revision cache (and I see you’ve increased the size of the revision cache in your config), but there aren’t any guarantees about availability for obsolete revisions.