caching issue

Hello, I notice that certain pages, where I have custom css, sometimes load a different style/template before it shows the correct one. So for like half a second my website looks very odd and then changes to the correct layout. This also happens when it's not the first visit. What should I do so that my site loads correctly from the start? I do have caching activated. I use WP Rocket and my hosting has its own caching: Kinsta Caching. Thanks in advance, really appreciate it :) Enjoy your free day off on Monday. Gijs