drill down - different symbols

Hi,

from time to time I have to maintain "old" Power BI reports. Line charts in "old" reports have a drill down symbol as shown in the picture below.

Newly created reports have a symbol as shown here:

This confuses the end user.

Is there an easy way to update the symbol to the new version?

- open / resave and republish the report does not help.

- old reports are opened / saved with the latest Power BI Desktop version

- I see the same difference in Power BI Desktop and in the cloud (old and new design)

Thanks for any help!