In the most recent year, in 2019, Google Analytics reports showed a lot of bugs and data errors.
Real-time report
Recently, there was an error in the real-time report of google analytics. The value of Active users on site is the number of people who are online in real time.But sometimes it will become a cumulative number in a short period of time. As long as there is access, it will increase. After a while, it will become real-time, the original number.
There are many other users online who have this problem too:
This is not your fault, it is a GA error, an estimated bug, waiting for the official fix.
Benchmarking
Look at your Benchmarking report. Is there no data? This report has no data since September. Many Google Analytics have nothing to do with data, I think it may be all.
Everyone did not make any adjustments and suddenly there was no data, so it is estimated to be a bug.
Demographic
Update, this has been fixed (2020-01-20)
Recently, the Age report in Demographic has been greatly reduced since December 18. The multiple accounts I manage and the official demo of Google Analytics have the same problem, so this is also a bug.