While almost everything is great about Bitwarden, the 5-8 second delay when performing a search is ridiculous (considering I have about 100 records), and I'm considering paying for a better maintained alternative.
I am on macOS Catalina although that shouldn't matter. I suggest you contact support https://bitwarden.com/contact/
Could it be a device issue? I highly recommend you report it to Bitwarden as Android can be a real pain in the ass to test with so many different devices out there with all kinds of strange OEM "optimisations" to the OS.
Maybe its a syncing related issue, try contacting support.