db.subscriber.ensureIndex({
mnoId : 1,
status: 1,
suspended : 1,
crmEvents : 1
},
{ name : "ix_cvr_invite_1"
})

WORKS:

db.subscriber.find({
"mnoId" : "4ee0c5e898452dd133f84e9d",
"status" : "TO_INVITE" ,
"suspended" : false ,
"$and" : [ { "profiles" : { "$elemMatch" :

{ "name" : "Language" , "values" : "English"}

}}],
}).sort({
"crmEvents.0.timestamp" : 1
}).hint("ix_cvr_invite_1").limit(30000);

BROKEN:

db.subscriber.find({
"mnoId" : "4ee0c5e898452dd133f84e9d",
"status" : "TO_INVITE" ,
"suspended" : false ,
"$and" : [ { "profiles" : { "$elemMatch" :

{ "name" : "Language" , "values" : "English"}

}}],
}).sort({
"crmEvents.0.timestamp" : 1
}).hint("ix_cvr_invite_1");