I have a adsense site was requested to be moved to a new server and use a different adsense account. So I moved the site files over to the new server, updated DNS, went into adsense and replaced all the old ads from the original adsense account with new ads from the new adsense account. I have done this before on previous sites. Anyway this was less than 24 hours ago. Traffic looks like its going to the new server just fine, however adsense wise the CPC is half then what it was under the original adsense account and noticing junk ads displaying and even duplicate ads displaying. Is this something that will eventually resolve itself? Or was something done wrong? The new adsense account has other sites and they average far less CPC, in fact the average is less than 20 cents.

Also noticed an error message in the original adsense account:
Earnings at risk - One or more of your ads.txt files doesn't contain your AdSense publisher ID. Fix this now to avoid severe impact to your revenue.

I dont even know what ads.txt is, never used it. There was never a file to begin with but its saying to add this file to the site. Do I need to do that with the new adsense account on their server with their publisher ID in the ads.txt file? Just confused whats going on, never had this issue before when I moved sites over.