Thank you for submitting a ticket with us.
File mask option is case-sensitive. Please check that the file and the mask have the same name - lead or Lead.
We do not recommend to use seconds or fractions of seconds, and even minutes in the mask, since it's not guaranteed that package will run in exactly the specified time.
When package runs, the date/time of the run is converted to the specified timezone, the specified date/time format string is applied to it, and the result string is substituted for the name fragment enclosed in braces.
You need to specify current date/time for a file name to make Skyvia to fetch it.
Also, please check that the file is not corrupted and correct CSV options are selected.
You can refer to these links: 1 , 2
We are looking forward to hearing from you, should you have any further questions.