Query with date calculation function works fine in the past - no more today!

Hi all,

We use in some reports a web request with a "start date" parameter. For this parameter we use a function to calculate a date in the past. 

Example: fktGetStartDate(10) means today minus 10 days.

In the query we combine this function with a text:

www.example.com/data/?IT_LDDAT=[{'SIGN':'I','OPTION':'BT', 'LOW':'" & fktGetStartDate(10) & "','HIGH':'20231231'}]

In the past it works fine! Today we get this error in Power BI:

My current PBI version is 2.112.1161.0 64-bit (Dezember 2022)

What exactly is the problem now? And how can i fix this?

Thanks

Torsten