App receive TIME OUT from mongoDB

Hello, I’m Jessica,
I have one mongoDB community the same way:
shard with two replica set.

The app is in Kubernets and somes mongos are in cluster to.
But tha app is receive TIMEOUT of the mongo, but I dont understand why this.
Someone can help me please?

I get the Information in the secundary:

2020-06-18T06:28:44.363+0000 I ASIO [NetworkInterfaceASIO-BGSync-0] Ending idle connection to host :27017 because the pool meets constraints; 1 connections to that host remain open