Hello,
I got a chance to install BuddyBoss and try this out.
The problem you encountered occurs when the following setting is turned on:
BuddyBoss -> Settings -> Privacy -> Private REST APIs
If you turn this off, then validation links will work again.
The response you got appears to me as if it’s canned. I am not sure if they checked their code. Did you explain to them everything I posted here, including the fact that the REST API of other plugins (Event Tickets and Registration) is affected? The plugin is actively disrupting access of other plugins to the WP REST API. If it’s a security feature then maybe it works as intended, but it seems a little strange to me.
In any case, you can turn off this setting and use both plugins together.
Hope this helps.
with regards