Text glitch with higher fps

[martynak6397272]

Hey, my problem is I'm making some short videos, and it contains 1080p 50fps vids from camera and downloaded from youtube lower fps vids.
And when I try to put simple text on it with Type Tool and export all to: 50fps software cbr50 1080p then text on that 1080p 50fps vids from camera is okay, but when the scene changes to text on youtube video then its starting to glitch.
Everything is fine however with 29,97 fps export setting - but I wanted to export everything to 50fps.
Why this text putted on YT vids in premiere is glitching? What causing the problem?

[Ann Bens]

...so we dont have to download unknown files: we help you, you help us. Thanks! 

[martynak6397272]

done