Cannot link backend with a preexisting Azure Static Web Apps configuration.

We have multiple static webapps that we want to point at the same Azure Functions backend, primarily because the logic behind the apps is the same and needs to be able to clear the cache from the other frontends, but the frontend differs significantly (otherwise we'd try do it in one SWA).

When trying to link the second SWA with the same func we get the error "Cannot link backend with a preexisting Azure Static Web Apps configuration. "

Is there some reason for this limitation and any known work arounds?