Hi @frju365 sorry for the delay.
As you can imagine, I’m really busy to find some time to create e-learning material. And you can easily find create existing lessons and tutorials on free websites such as:
Personally I find real projects more instructive than tutorials. I’ve always looked for small and concrete projects to learn some new technologies (e.g. do a friend’ e-shop website to learn Sylius). It can be stressful because you’ll have to deliver something no matter you don’t know at the beginning but you’ll learn twice as fast 😄.
I find Symfony official documentation really well-written too.
I can’t recommand any non-free e-learning websites as I’ve never bought paid tech lessons. But a good idea would be to list Symfony Core team members and search if one of them has already authored some video or books (besides Mr Potencier).