Advocate IVThanks v-yingjl for looking into this,
Adding more information on this issue:
I am on the latest version of Power BI desktop. At the moment: Version: 2.96.1061.0 64-bit (August 2021)
The issue doesn't happen on Power BI desktop where the hover over behaviour is as expected.
When I publish the same report to Power BI service the issue appears even if it worked correctly on Desktop.
The issue happens on the Service and also on Embedded.
The issue continues to happen if I create a new report and paste the affected visual on it or add new line chart visual with the same data.
The issue doesn't happen if the line chart is based on data from Columns.
The issue happens if the line chart is based on data from Measures.
In this case I am using data from a column on the X-axis and data from a measure as on the Y-axis (on the "Values" section) having a data from a calculated column on the Legend section.
We see the issue on multiple browsers and multiple users.
Thanks