I have been struggling with WES as well. The timeline is like
For me:
Docs delivered by FedEx: 31st Aug
1st update (we have received your documents, we are reviewing your documents): 4th Sept
2nd update (we have received your documents, we are reviewing your documents): 12th Sept
3rd update (Your evaluation is in progress, Your evaluation is due for completion on 10/15/2018): 23rd Aug
For my wife:
Docs delivered by FedEx: 31st Aug
1st update (we have received your documents, we are reviewing your documents): 3rd Sept
2nd update (we have received your documents, we are reviewing your documents): 11th Sept
3rd update (Status: On hold, We are waiting for your institution(s) to verify your documents.): 19th Aug
I don't know if the institution responds to WES for such verifications. WES doesn't even share the email to which they send the verification emails, and have a painfully long follow-up date of 7 weeks i.e. if they keep on waiting for 7 weeks for a response from the institution and then only send a second follow up and wait again for a response for yet another 7 weeks. :-(