Hello,
Firstly, I would like to sincerely apologize for the delayed response as we have been experiencing an unusually high number of tickets. I am sorry that it has taken longer than usual to respond to your concern and your patience is highly appreciated.
Yes, we had a bug for the charts not properly rendering the X axis for Date values, but our developers fixed it with a quick update.
Can you please check, whether if you are using the premium or free wpDataTables, just make sure to update to the latest version and this issue should be fixed?
If it is still happening, please confirm which version do you have installed ( and if you use premium/or Lite Plugin) and we can double-check it.
Thank you.