Hi there! The site being down for so long could definitely be contributing to the drop in revenue, as that would have been a span of about two months that Ezoic wasn't able to gather data on the site and adjust placeholder setup, etc. It's also important to keep in mind that November and December are the times of the year when ad rates are at the very highest, so you won't see ad revenue as high at any other time of the year just due to the nature of how ad rates function. From the chart you sent, I can see your revenue is already climbing back up to around where it was in January, which is when publishers will typically see a sharp drop in revenue as the holiday season comes to an end. The upward trend in revenue is encouraging as well and indicates that Ezoic is adjusting and re-learning the best optimizations for your site.
But, if other changes were made on the site after this issue occurred, these could also be contributing to overall lower revenue. First, it looks like you don't have Adsense linked to your site, which isn't necessary but can definitely help maximize your revenue through Adsense Mediation. If you have an Adsense account I'd strongly recommend linking it with Ezoic to make sure you're getting the very highest revenue you possibly can from every ad placeholder through Mediation.
I'd also recommend taking a look at our EPMV best practices to make sure you're doing as much as you can to help maximize your revenue: https://support.ezoic.com/kb/article/ezoic-best-practices-for-higher-epmv-earnings
There's also these general guidelines for troubleshooting drops in EPMV/revenue that might be useful: https://support.ezoic.com/kb/article/troubleshooting-epmv-changes
And finally, this interactive article will help give personalized suggestions for your site on specific things you can do to maximize your EPMV: https://www.ezoic.com/epmv-your-website/