An error occurred while saving the commentejmick commented
I have also experienced this. Small deployment, 5 users, 3 Poly CCX phones. Calls run through Auto Attendant (for scheduling) then to Call Queue to ring all users (Attendant Routing). When phones are in place, call presentation is delayed 3-10 seconds. When answering the call from the client or phone, response is very sluggish in that audio doesn't cut through for a few seconds. When phones are removed and run as "client only", performance is much improved. Not perfect, but about as you would expect. Customer feels as though they gave it a shot, but wants to replace it with something else.
As a partner looking to build a Teams Voice practice, this has us considering going back to our previous voice offerings. To Microsoft support's credit, they acknowledged this as a "known issue" and have engineers investigating a workaround and/or permanent fix. Hoping for a quick resolution to restore the faith.