I have the same issue. It is a very non-sensical issue and frustrating that there is no response from ESRI. Dates and times are a common category used in charts. They are available in the ArcGIS Dashboards charts. I am simply trying to duplicate an ArcGIS Dashboard in Experience Builder so I can have some control over the responsiveness of the layout on the smaller screens. Unable to duplicate even the simplest of charts with this issue.
I am in the same frustrating position of duplicating functionality from Dashboards into an Experience Builder project. Esri seems to always focus on the fringe benefit kinds of enhancements in their product releases, but they often miss the basics, while we wait years for implementation.
One more person asking about this improvement. Same situation as the previous post.
It seems that serial charts do not use dates. It would be great if someone from ESRI could let us know if we can expect this improvement. Thanks a lot.