Sync Gateway sg_access_x1 index error

I am receiving below errors sometimes on Sync Gateway Server

Sync Gateway version: 2.7.2
Couchbase Server: 6.5
Data size of index sg_roleAccess_x1 is < 5 MB

Access query takes sometimes more than a Minute.

2020-04-16T20:55:49.227+05:30 [WRN] Error when querying index using statement: [SELECT meta(`kamero`).xattrs._sync.access.`role:event_viewers` as `value` FROM `kamero` USE INDEX (sg_access_x1) WHERE any op in object_pairs(meta(`kamero`).xattrs._sync.access) satisfies = $userName end;] parameters: [map[userName:role:event_viewers]] error:[1080] Timeout 1m15s exceeded -- base.(*CouchbaseBucketGoCB).Query() at bucket_n1ql.go:76
2020-04-16T20:55:49.227+05:30 [INF] Query: N1QL Query("access") took 1m16.853335036s
2020-04-16T20:55:49.227+05:30 [WRN] QueryAccess returned error: [1080] Timeout 1m15s exceeded -- db.(*DatabaseContext).ComputeSequenceChannelsForPrincipal() at crud.go:1783
2020-04-16T20:55:49.227+05:30 [WRN] channelComputer.ComputeChannelsForPrincipal returned error for &{Name_:event_viewers ExplicitChannels_:channelOpen:314 Channels_: Sequence_:314 PreviousChannels_: vbNo:<nil> cas:0}: [1080] Timeout 1m15s exceeded -- auth.(*Authenticator).rebuildChannels() at auth.go:174
2020-04-16T20:55:49.227+05:30 [WRN] RebuildChannels returned error: [1080] Timeout 1m15s exceeded --

Could you please suggest what should I do to avoid this error?