Adsense account - Ad serving has been limited?

I have been experienced this temporary issue couple of times earlier. Then I figure out I'm generating invalid impressions through visiting my own website. After that, I start to use an ad-blocker which resolve the problem at that time.

This time without any clue my account has been limited and the issue is "Invalid traffic concerns". I'm sure I haven't generated invalid impressions this time. My server was down for a couple of hours because of a different issue and that incident is what happened (something highlighted) prior to the limitation (a day ago).

Can someone please help me to sort this out, I'm aware that I have to wait 30 days. But I want your help to understand the situation and try to avoid it in the future.