Pasting password on Android

I use an external password manager (Keepass) which allows me to paste passwords into login pages. Since a recent update of Firefox on Android (currently running 28.0.1), long pressing an input field does not pop up a menu, but instead changes the header bar (where the search/URL field and tab buttons are) to show buttons for copy, cut, paste and search. The issue I'm having, is that when long pressing a password field, a single option pops up with the text "Save login information", apparently to force the built-in password manager to store the username and password for the current site. This change makes it impossible to paste passwords using the standard (long-press field) method. Instead, I need to use an external keyboard, or a keyboard that has a CTRL key (e.g., Hacker's Keyboard) and C-V to paste the password. Is there another way around this? Perhaps disabling the "save" option or adding a secondary "paste" option for password fields? EDIT: Turns out this wasn't due to an app update but an installed addon, called "Mobile Password Manager".