Search doesn't work on multi-network

I am running the latest version of the plugin along with WP and BP. I checked off all of the search types and ran this in a sub-site of a regular multisite network and it worked fine. I tried running it on a sub-site of a multi-network (or multi-db) and the plugin doesn’t pick up anything in the search results. Is there a reason why it doesn’t work on multi-network (multi-db)?

Thank you.

https://www.ads-software.com/plugins/buddypress-global-search/