Serious problem with AP+WDS

We’ve noticed this weird problem lately with our Mikrotik AP’s using WDS with stations (bullet2). I posted a screenshot. The Mikrotik lists each WDS on the interface tab (wds1,wds2, etc) as pulling the same amount of traffic. At night, the WLAN interface will show up to 15Mbps eating up all available bandwidth, and each WDS interface showing the same traffic (1500-2.0Mbps).

Any suggestions?

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maybe you are sending some broadcast traffic?
What RouterOS you are using?
Try to sniff to check what kind of traffic it is.