When copying strings from anywhere on the computer and trying to paste them to Linux Editor, nothing appears.

Steps to reproduce:
1) Start the Linux Editor while logged out of your account.
2) Type your username somewhere (text editor or browser address bar for example).
3) Copy the username to clipboard.
4) Attempt to paste it in the Editor username field.

No text appears. When text is copied from somewhere inside the Editor, it can be pasted properly.
Values copied from the Editor cannot be pasted outside as well.

Reproduced on:
5.6.0f1, 5.3.6f1