Web contact sheet names

Using C1 21, 14.3.1.14 on Windows, I batch renamed a bunch of pictures to make them more user friendly. The new names now appear when working in C1, but the files were not renamed on disk. When trying to create a web contact sheet after selecting pictures, I get the original (camera/disk) name of the pictures in the web sheet.

How can I use the name I chose in the web sheet? As the original name is not displayed anymore in C1, linking between original and shown names will become a headache afterwards.

P.S. I re-installed previous version 14.2 on another computer to test. There the disk files are renamed, and the web contact sheet is in line with both the file names on disk, and the displayed names.

Is there a way to force the rename on disk in 14.3 ?