Switch from Inertia to Inertia SSR made no change in render speed

Im developing a website using Laravel + Inertia + Vue js, i decided to switch to Inertia SSR for better SEO and faster First Contentful Paint as i want my page to load content as fast as possible. Before switching i decided to run a Lighthouse test on a simple page of my website, the results where:

Perfomance: 89 | SEO: 73 | First Contentful Paint: 1.5s

I also tested the same page by disabling cache and throttling to Fast 3G, the results where:

DOMContentLoaded: 7.40s | Load: 8.16s

After changing to SSR i ran another Lighthouse test to see the change in speed and the results were EXACTLY the same. I think there is clearly an issue with SSR because when i tried the same 3G test with Javascript disabled i got clearly better results:

DOMContentLoaded: 1.21s | Load: 2.84s

I get that the Load is faster because there is no Javascript, but shouldnt the DOMContentLoaded always be 1.21 because of SSR? (I couldnt run the Lighthouse test as it needs Javascript to be enabled).

Also, on the Inertia page there is a section inside SSR talking about Client Side Hydration, i thought maybe that was the problem but changing to "Create SSRApp" didnt change anything. https://inertiajs.com/server-side-rendering#client-side-hydration

Why is my page speed not changing after i switched to SSR?