I've found a couple of things that have worked for me on iPhone XR, #2 below working the best so far:
1. Reinstall the app:
This would usually get me a few weeks of 150 credit videos per day, at first without restarting app, but after a week or so having to restart and/or toggle ad tracking. You'll have to log in and briefly set up the game again, but it doesn't take long. Eventually it'll fade away and you'll have to reinstall again.
2. Toggle ad tracking for the app only:
I didn't realize that you can toggle ad tracking by the individual app rather than the whole phone. I had been toggling the master ad tracking button for the entire phone instead of only toggling ad tracking for the WGT app. If I leave the master ad tracking switch on, and only toggle ad tracking for the WGT app itself, I tend to not have any issues reaching 150, and only have to restart the app once or twice, and toggle ad tracking once or twice a week. I've been doing this for about a month now, so far so good.
All of this is with personalized ads turned off.
Sorry for the android folks, this is all I got, hope it helps.