The Google AdSense support team will be offline from December 17, 2021 to January 4, 2022 - a full 18-days. Google said the team is going offline for the holidays and that you should use the help forums and self help during that 18-day period.
Google posted this notice at the top of the AdSense Help Forums saying:
Welcome to AdSense Help Center. Due to the holiday season our support is currently unavailable from 17th December to 4th January. We encourage you to visit our Help Center and community forums for additional resources. We apologize for any inconvenience this may cause and appreciate your patience during this time.
Yes, that is an 18 day period where you will be unable to get direct support from a Google for AdSense publisher related issues.
I assume this is not a huge deal and that generally it is hard to get support from the AdSense team directly but I wanted to make sure you all know that the AdSense support team is offline starting this Friday, December 17th, through Tuesday, January 4th.
Forum discussion at AdSense Help Forums.