Backspace no longer deletes letters, happens only in FF app

hi, I have this odd issue lately that when I type something in the browser, search engines in particular, then hit the enter key on the on screen keyboard, and then click inside the same inputfield again that the backspace button switches behavior and no longer affects the text field but deletes the last letter from the word in the auto-correct-suggestion panel diirectly above the keyboard. clicking back into the browsers textbox doesn't help either. I have to press backspace several times until auto-correct stops suggesting new words, (turning off auto suggest doesn't fix it) then focus returns to the inputfield in the browser I can repro it with multiple keyboard apps (microsoft & heliboard), on different search engine websites but it only happens in Firefox not in chrome nor any other Android app. I also noticed that when I move the text cursor somewhere with a tap in this input field and then hit backspace, then it will show the context menu (copy, paste, insert...) for less than a second and instantly close it again. Pressing backspace a second time doesn't trigger it again until you move the input cursor with a tap again. I only use uBlock but disabling it didn't help. Phone: Nothing 3