I have never, ever seen this before. I don’t even know how the table was created with a different collation. However, I had all my other tables created with the character set utf8, no collation specified.

I had to convert the second table to match the character set. This probably wouldn’t have been a problem if I wasn’t joining on a character field.

alter table exclusion CONVERT TO CHARACTER SET utf8;

First time I’ve ever seen that one.