Check your Access-list and NAT configuration.

Does a PC connected to the same switch port get an IP address?

When you connect a phone/laptop to a switch port on the new 3850, what do you see on the switch logs?

I'm guessing that your are using icmp (ping) to test the connectivity between the VLANs.   Your ACL is blocking the traffic going in to VLAN 50 from other VLANs (except VLAN20)   Example - Packet from VLAN 30 (192.168.30.5) to VLAN 50 (192.168.50.5) ...

I found a fix to the issue.Ping the ATA 187 to make sure there is connectivity.Using Putty Telnet (Not SSH) to the device on port 7870.You will get a prompt as this / #Enter the command "reboot cli"After few seconds, the ATA will re-register with CU...