I also figured out my issue… onlu install the updater plugin on on the network. upload the platforms/themes, but don’t network enable them.
On the subsite, activate the platform and theme and then everything works on just the one subsite.
I don’t know if you guys found an answer already, but to make buddyboss work on a multisite you have to use their updater plugin https://www.buddyboss.com/tutorials/buddyboss-updater-plugin/
Then once you enter the key from the network admin you can apply the settings on the backend of one subsite… though I’m having issues with the registration being limited to just that one subsite, so take this with a grain od salt.