16.40Scenario: suddenly many Salesforce timeouts

Check:

Salesforce service degradation?
network?
Mule connector configuration?
recent connector/runtime upgrade?
request volume?
Salesforce locking?
API limits?

Current connector 12.0 release notes even include a fix related to read-timeout handling for internal DescribeSObjects calls, illustrating why connector/runtime versions can matter in troubleshooting.