External table validation weirdness

[Dagel]

I have a shadow MySQL table in FM to which I've been able to write data for well over a year. Now, all of a sudden, when I try to change any field data, FM is seemingly trying to validate fields in the MySQL table which it never has before. Nothing has changed in my ODBC connection, FileMaker or the table itself (I can write directly to the table via Navicat without validation errors). Has anyone ever encountered anything like this?