I was able to import from Mysql to MariaDB simply by adjusting the export SQL settings in PHPMyAdmin.
I changed from the default statement e.g:
INSERT INTO tbl_name (col_A,col_B) VALUES (1,2,3), (4,5,6), (7,8,9)
to:
INSERT INTO tbl_name VALUES (1,2,3)
It seems like this was the issue that caused the error. Once I re-exported, it imported into Maria DB fine.