Real time GA is up and down up and down .... WTF

For two days my real time G Analytics organic ("google") traffic changes suddenly in every 25-30 sec:
20 online
50 online
20 online
50 online
....
30 online
60 online
30 online
60 online
etc.
all day.

I tried:
- Tagmanger code changed to simple Analytics code
- Server restart
But the "up and down up and down" doesn't stop. These changes happen in 1-2 sec.
Any idea?

Try to track traffic by other methods. Start with free. For example Hotjar. Compare the results, and then draw conclusions. this sometimes happens with analytics. I wish you good luck, my friend!