tmo Ah that's great thank you for clarifying.
In terms of why the ad revenue index doesn't match in with Seasonal expectations this article can help you with in depth understanding of this: https://www.ezoic.com/why-ad-rates-are-so-low-in-q4-2022-and-q1-2023/ The article is updated regularly to help Publishers understand the changes in the wider Publishing space.
For your site if we compare March to the same period in December when your EPMV was at it's highest the traffic has dropped by 34.62%, the time on page has dropped and the bounce rate has increased.
There has also been a big jump up in pages without revenue: https://analytics.ezoic.com/reports/content/pagesWithoutRevenue these look to be different variations of your home page which you have blocked ads from showing on
The biggest percentage of your readers access your site through a mobile rather than a desktop. The mobile screen is smaller and so the ads are cheaper for advertisers to buy.
In terms of the next steps, I have taken a look at your website and can see that there are key ad placeholders missing - are you ok if I update these for you? thank you