Hi,
if we are saving a workflow instance the form validation is ignored. This includes regular expression. In my opinion the regular expression should be checked and if they are not successful, saving should be prevented. Otherwise we will be able to save invalid data, which in turn can lead to issues, if the data is used in other workflows.
In our case the field can be used as the display name of choose fields and we wanted to prevent the use of the special characters ; and #.
The attached image has been taken from 2024.1.1.88.
Best regards,
Daniel