On a daily basis we have to restart MongoDB nodes (secondaries and primary) because performance degrades dramatically.

We can observe the percentage of WiredTiger cache (%use column when we use mongostat command) in use are freezing to 100% (and this percentage never decrease by it's own if we don't restart the node).

After the node has been restarted, the %use decrease to ~80% generally.
I've added an attachment of a graph displaying the %use on our servers.

We tried to increase the cacheSize parameter.
Here on a 64GB server:
wiredTiger:
engineConfig:
cacheSizeGB: 56

The issue is still the same even with this configuration.