When processing a JDBC payload with a JDBC Probe, an argument in a datetime field like now() used to get evaluated and the field value was that of the current date and time. Instead the now() function failed to get evaluated because the value is passed between quotes.
Evaluating such arguments from a function like now() proved to be a security risk and engineering decided to discontinue this functionality.
For example, when trying to pass function now(), simply use a trigger in the destination database instead.
More information can be found here: https://dev.mysql.com/doc/refman/8.0/en/triggers.html