Mikrotik Wirelss Uplink and Switch cisco Loop Detect

Hi Dear Friends
I have Problem With mikrotik Radios
If used Only Bridge Wlan and Ether When Connect Cable To switch cisco Switch Get Loop Detect and Err-Disable The port

When Used WDS and dynamic wds Enable on Radios Donnot Get This loop and Trunk Work Good

Please Tell me why this is happen In mikrotik Radios

THX