Fillip
I've never used Blocksy Theme Pro so I'm not familiar with its features. But I have used Leap with three different themes and learned a thing or two along the way. Maybe one of the following will be helpful.
1) I learned that I should not use similar CSS management features in the theme and Leap at the same time. There is a high chance that there will be a conflict. I don't know about Blocksy, but some themes such as Avada include CSS management features that you can use or not. Just don't use the same settings in Leap and your theme.
I currently only use Leap's CSS features to optimize fonts. I do not use it for Critical CSS or to Remove Unused CSS. If I were in your shoes, the first thing I would do is completely disable Leap's CSS features. See if your menu issue resolves itself. If it does, and you still want to use a Leap CSS feature, activate it again and see if your menu breaks. If it does, disable that Leap CSS feature. I find that I do not need all of those features anyway. They are mainly there to replace similar features found in some themes like the Avada theme and in some plugins such as WP-Rocket.
2) I'm not trying to contradict Blocksy's support, but I would leave the Ezoic CDN running. It can have a positive effect on your site's page speed. If you make any changes to your site, and you see problems with it on the front end, clear the Ezoic cache. You can clear it site-wide or for a single page. You can do that at Ezoic > Leap > Caching > Clear Cache.
3) If you also use a caching or page speed plugin, it may conflict with Ezoic, causing some weird issues. Some time ago, I was able to successfully use WP-Rocket and Leap together. Changes that have been made to the Ezoic WordPress plugin make it so that is no longer the case. Use one or the other, but not both.
4) If you use custom CSS, add it in WordPress, not in Leap > CSS.
5) Get used to clearing your browser caches after making changes. If you don't see your changes then, clear the Ezoic cache or any caching that your web host has in place.
6) I've found that I may see different (more accurate) results after making site changes if I view the site in a private browsing tab. If you clear the browser cache for your site, also be sure you clear any cookies that your browser has collected from the website you are having trouble with.
7) If things look wonky and nothing else seems to help, and you don't want to view the site in private mode, be sure you log out of WordPress if you are viewing your site in the same browser that you are working in WordPress.
8) If you have a CDN at your web host in addition to the Ezoic CDN, issues could pop up. In my current situation, I successfully used the CDN at my host along with the Ezoic CDN. It helped me get better times from the origin server. That setup worked fine for quite a while until one day, suddenly it didn't.
I'm not saying that all of these things happen all of the time or with every website. But they are all things that I have experienced in the time I've been with Ezoic.
I hope this helps.