I work mostly on Zen mode, which is faster, I use from time to time to switch to another tab where I have an online translator like DeepL or Google translate, when I'm not 100% sure that my TL is correctly or the idea is harder to convey and have to check if my translation is on point with the idea or so.
I have noticed that, if I try to copy a phrase or paragraph and did not finished correctly the translation, the system will get a bug whereas if I try to copy another phrase or paragraph, using the dedicated button, the system would use the last copied item, before the bug happening, instead of the actual one that I'm trying to use.
Furthermore, the bug catches the Crtl+C command and overrides it, so I have to mark the text I want to check with the translator, and press multiple times (at least 5 or 6 times) the Crtl+C command, in order for the system to recognize that I want that piece of text copied, if I do Crtl+C once, it will still use the last text copied before the bug.
The bug is agnostic to the web browser used, have tested in Brave, Chrome, Firefox and Edge, and it can be triggered in every single one