SYS_REPO also needs grantable select access to read the table holding the allowed values. Looks like the error is that this user can't read the tables.
Try this
GRANT SELECT ON "MySchema" to "_SYS_REPO" with grant option;
Also - you don't mention anything about where the data supplied to the Analytic View is sourced from, is it also from "MySchema"? If not, SYS_REPO also needs grantable SELECT access there.
One thing to try is to remove the dynamic AP from the role and give FULL (all data) access to the Analytic View to that role. If it doesn't work at this point, then something fundamental is wrong like my second point above.
Regards,
Justin