With the Ezoic ad tester, you are encouraged to place between 15 and 30 Ezoic Placeholders on each page to get best results. These are potential (temporary) ad locations where an advert could go. Ads won't display in all these locations at once unless the system has gathered data from the user that demonstrates this is their individual preference.
When you are are seeing lots of ads, this will not be the same for every other user. Ezoic has improved ad locations and UX and revenue as a result for thousands of publishers in this way.
The longer you give the system, the more data it gathers, and the better it optimizes your site for each user.
Ezoic will never display more ads than you want it to- you can change this setting in your Dashboard using the Max Ads Per Page App. It is best to leave this at 'Automatic'- the system will not display more ads than Google allows.
On pages with long content, sometimes the system will test with more than 5 ads per page - the additional ads will not be Google Ads, but ads from the many other networks we work with, like Criteo for example. Remember, the system is testing some pages with more ads and some with fewer; all the while measuring impact to user experience.