Mongo db primary shard callig old aggregation when api get hits

We have changed our aggregation code from node and hit mongo its applied and works for some time, after a day if hit means its showing old aggregation in shard what is the issue.

ex: we have 3 replica sets, we deployed our API yesterday to check our keys examined in mongo. That time it was working fine. but today when we saw it is showing the old code that is not exists.

Where are you seeing this happen? I think a support case will be needed, there’s not enough info here