ORA-16552 an error occurred when generating the CLIENT OPERATION table Cause An error occurred while Data Guard broker was generating the CLIENT OPERATION table. Action See the next error message in the error stack for more detailed information. If the situation described in the next error in the stack can be corrected, do so; otherwise, contact Oracle Customer Support.
If you have a metalink username and access privileges, please also check the metalink for relevant articles. Your data guard status looks fine and i do think the switchover happened at the end but not from the data guard broker.
Oracle Error :: ORA-16501 the Data Guard broker operation failed Cause The Data Guard broker operation failed. Action See accompanying messages for details.