Unity Ads have suddenly stopped working in my newest build

Newest version of IAP and Ads, Unity 2017.2.0f3:

Worked great for the past three months, and then suddenly, ads stopped getting served to the game.

I did a debug and see these lines:

2018-06-16 00:40:51.971794-0500 weaponaire[705:164617] I/UnityAds: +[UADSApiSdk WebViewExposed_logInfo:callback:] (line:59) :: Requesting ad plan from https://auction.unityads.unity3d.com/v4/games/1652612/requests?advertisingTrackingId=E9EE75D3-9ABF-4E12-98AF-211D930E0D85&limitAdTracking=false&deviceModel=iPad7,4&platform=ios&sdkVersion=2201&stores=apple&osVersion=11.2.6&screenScale=2&screenWidth=1112&screenHeight=834&connectionType=wifi&networkType=13
2018-06-16 00:40:53.686347-0500 weaponaire[705:164617] I/UnityAds: +[UADSApiSdk WebViewExposed_logInfo:callback:] (line:59) :: AdPlan received with 3 campaigns and refreshDelay 3600
2018-06-16 00:40:53.811998-0500 weaponaire[705:164617] LTE
2018-06-16 00:40:53.814506-0500 weaponaire[705:164617] E/UnityAds: +[UADSApiSdk WebViewExposed_logError:callback:] (line:49) :: {"message":"No video URL found for VAST","name":"Error","stack":"getVideoUrl@file:///var/mobile/Containers/Data/Application/0B2A82DC-D9DB-4A9F-BB9D-FFE9A965C214/Library/Caches/UnityAdsWebApp.html?platform=ios&origin=https://webview.unityads.unity3d.co...16c70bbfc0abbfe0:7400:37\npromiseReactionJob@[native code]"}
2018-06-16 00:40:53.927868-0500 weaponaire[705:164617] LTE
2018-06-16 00:40:53.930303-0500 weaponaire[705:164617] E/UnityAds: +[UADSApiSdk WebViewExposed_logError:callback:] (line:49) :: {"message":"No video URL found for VAST","name":"Error","stack":"getVideoUrl@file:///var/mobile/Containers/Data/Application/0B2A82DC-D9DB-4A9F-BB9D-FFE9A965C214/Library/Caches/UnityAdsWebApp.html?platform=ios&origin=https://webview.unityads.unity3d.co...16c70bbfc0abbfe0:7400:37\npromiseReactionJob@[native code]"}

 

Just started getting this error too! Ads were working fine this week for me, but when I built a new version today and ran it on my phone, I got the message "No video URL found for VAST" in the console log. I'm on 2018.1.0f2.

 

@rasmus-unity - putting up the flag for Unity now - this is a really odd error, because I can get one or two ads to play when I first start the app, then after that there are none available as many times as I try. I rolled back the version of ads and IAP, but still the same behavior, which is making me think this is not something related to my local game, and possible a server malfunction of some kind, like it thinks that I've exceeded daily ads, even though I haven't...