Text Editor is still buggy in RTL. (F7 5.1.0)

When using an RTL language like persian, in multiline texts, you can’t select text using mouse.
Also copying to clipboard doesn’t work at all.

Using F7 5.1.0 on a Debian system and with a recent version of Firefox as browser.

Is there any hope of fixing these soon? Thanks!

It is not related to F7, it doesn’t do anything with selecting text and copy to clipboard.