My add-on (see https://addons.mozilla.org/en-US/firefox/addon/automatic-dictionary-switcher/) stopped working with FF44 due to a bug/change in FF, so I set the maximum compatibility of the latest version to 43.* in the web interface. But I still can find the add-on with FF44 and see the “+ Add to Firefox” button. Shouldn’t installation be prevented in this case? Will I need to hide it completely to avoid confusing users?
For such situations, we can add a compatibility override so the add-on will not appear as compatible with 44. I did that just now for yours, so I think you can enable the listing again and it will work as you would want to. In the future, you can contact amo-admins AT mozilla DOT org to request this.