Randomly pasted text in Juno

Regularly, when using Juno, I get weird errors that result from random pieces of text pasted in the middle of my code files.

Not sure if this is particularly a Juno/Julia thing of a more general Ubuntu one, but it seems that some clipboard content ends up in the code when using copy and paste shortcuts for other applications or the REPL.

Is this a known thing? How can I prevent this?