Hey Marcel,
Sorry to say but oEmbed doesn’t work on the Text Editor module. We tried to make it work but ran into some technical roadblocks. We do have a feature request to get that working though, feel free to vote for it on the link below if you have a minute. 
https://wpbeaverbuilder.uservoice.com/forums/270594-general/suggestions/8227899-fix-oembeds-in-text-module
In the meantime, you can use either the Video module or the iframe code from YouTube itself.
Ben