We could not find any connectors in your environment .
Could you check a few things as below
1. Hope the environment in which you are working is the correct one. From the message it appears that it is related to environment
2.Close PowerApps, Clear cache, reload PowerApps and then try finding the connector again. See if that works
3. Create a dummy App and try to connect and see if that gives you some hint.
if it helps, please mark the answer as Verified.
Thanks