Problem with a foreign key referencing a primary key which is also part of an unique key (MariaDB)
MariadDB seems to handle it correctly. According to Fiddle the information_schema is correct, so the problem seems to be with your tools:
SELECT table_name, constraint_name, referenced_table_name, unique_constraint_name 
FROM information_schema.referential_constraints;

table_name          constraint_name         referenced_table_name   unique_constraint_name
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author_personal1    author_personal_FK      author1                 author_UN
work_authors1       work_authors_FK_author  author1                 PRIMARY