Here's a good video. Demonstrated with guitar, but same applies to other musical instruments.
#1 Skill
Have you found it is easier to stay in the pocket when you have either 1) earphones on loud and, or, 2) good loud drummer? That's also the way to develop chronic ringing in the ears. Alternative is to follow this instruction in practice. Hint: count the 1/8 and 1/16 notes until it comes natural to hear and recognize them.
Drum students will recognize what is called "paradiddles."

I have seen Claus Levin in other videos. He makes it looks so easy.... It ain't

I have had success with teaching rhythm with notation and 1e&a but most find it easier to use words: https://www.themusicolormethod.com/how-to-teach-rhythm-for-beginning-music-students/

Without rhythm you have chaos, or as some people say progressive jazz

Lotta good stuff on that musicolormethod site, Mario. Thx.
I learned: a-1-&-1-a-2-&-2-a-3-&-3-a-4-&-rest. and a bunch of variations. I think what he wants guitar students to do is get in the habit of counting the 1/4, 1/8. 1/16 notes while listening to the music or waiting for the train. (Might get some strange looks, but what the heck?)