We have already identified this issue (or perhaps behaviour would be a better word) last week and we’ll be working on bringing back support for having multiple instances of Piwik PRO in a single dashboard. This is due to the fact that the verified connector oAuth seems to be indeed linked directly to the Google account, even though we use a different authentication method in the product and we don’t request any Google account data in the connector itself.
As unfortunate as it sounds, I’d say that using the unverified version would be the best way to deal with this case until we release a fix. FYI - this issue and the one related to metrics aggregation are currently sitting at the very top of the priority list for the LS connector.