We know, to get Custom file name for Export data to Excel/CSV we need to give Title to Visuals. Since We dont want the title for our visuals, as a workaround we were turning the font size to Zero as shown below
Before March 2023 Update:
But after march 2023 update we are not able to set the title font to zero. we know still we can change the text color to make them invisible but it is more comfortable to change the font size to zero.
After March 2023 update:
Now the least allowed value is 8 like other properties
What is your previous version ? I tested with Version: 2.114.864.0 64-bit (February 2023) , the minimum value of font size is 8 . If it could be set to 0 before, then you need to provide your previous version number for us to test.