I've got one table on the host which has a mere 48,188 rows in it – although one is a LONGTEXT field – and the remote machine's version of it has 17,378 rows.

The longest value in that LONGTEXT field is 1,525,392 bytes.

When I attempt to run pt-sync against this table, even letting it run for several hours, the number of rows in the remote's table does not change in the slightest. (Even though I know it might be using transactions, I would expect them to periodically commit.)

And I simply don't know why not. I see the program churning away, but I see no visible progress.

(This is the version on "Ubuntu latest," running against two identical MySQL database servers, both also running the "Ubuntu latest" versions of both LInux and MySQL.)