Shotwell currently has an issue authenticating against Google Photots. This is caused by new OAuth scopes that I somehow missed. Apologies, a fixed Shotwell 0.30.11 will follow shortly once Google approves the new API scope
This has been fixed in 0.32.13 (.13 because I am stupid). Distributions should either upgrade to that or back-port 95511c476c23a78afb36437c498bf02359867ed5