A couple of my friends said the same to me.
I don't have a windows phone to confirm that.
It was very annoying. At first it only happened occasionally. Then it started doing on every call. The only way to get the screen back was to wait. I got to the point that I would either use the speaker phone or hold the phone away from my ear. I'm in my car that has Bluetooth so I haven't had a chance to test it. When I get home I'll see if the problem was fixed.
UPDATE 6/11: KB4505390 update Windows 10 Mobile v1709 Build 15254.572 - June 11
Source: https://support.microsoft.com/en-us/help/4500154
Windows 10 Mobile Specifications & Systems Requirements
UPDATE 3/15: KB4090912 Update for Windows 10 Mobile Build 15254.313 - Mar. 15 Mobile - Windows 10 Forums
Source: https://support.microsoft.com/en-us/help/4077675
Windows 10 Mobile Specifications & Systems Requirements