Tabs do not render until JavaScript is loaded.
Summary
The open tab content seems hidden until JavaScript is fully loaded. For example, when you go to https://flowbite-svelte.com/docs/components/tab#Default_tabs you will notice that no tab is open for a second until JavaScript is loaded. Refresh the page to see the effect again.
Can you show us your code?
Can you show us your code?
I rephrased it a bit but the code can be seen in the examples of the docs. Serverside rendering does happen but on the clientside the tab is hidden until JavaScript is loaded. Probably because it has the hidden class added to it.
I can see that when I use Chrome dev tool > Network > No Throttiling Slow 3G.