UDP no longer allowed to send on android 7+?

So I have been running an app on android (Samsung Note 4) with out trouble until the latest phones started coming out with android 7+ (Samsung S8, OnePlus3T). Now I find that UDP is blocked on the phone in the app. Is there a **new setting that blocks UDP broadcasts**? I used Evothings app to test that UDP is blocked. I noticed a change with the way WiFi works on android. If the WiFi connection doesn't have internet, the system seems to behave differently. Does WiFi work differently if there is no internet? Again, it still works with the older versions of android. If you have come across this problem please share.