From the comments, I think this is an Android-specific issue. I use Bitwarden on Android and also find that searches inexplicably take several seconds, especially when you arrive at the search query from the autocomplete popover.
This is exactly where I'm getting the delays. Which is indicative of another problem: in several websites I have to search for the login manually because Bitwarden doesn't find the credentials (according to the Android Firefox/Chrome extensions). This never happened with 1Password.
