The drop-down list with known usernames and passwords extends until below the screen if there is a sufficient number of usernames stored. The funny thing is that the list is scrollable by mouse and arrow (up/down) keys, so it wouldn't be necessary to extend the list that far down. Just until the lower boundary of the current firefox windowwould have been sufficient. The result is that I can't see (nor select) the usernames that are listed below the screen. Firefox 75 64 bit on Fedora 32. I hope this description was clear enough as I'm hesitant to include a screenshot showing all usernames involved on those site. For anyone who wonders why so many logins: it's a list of email adresses currently in use in a webmail service. Thanks.