RE Camera Raw 16 & DNG Converter 15.3 and Exif Tool

I am using Windows 11 and Camera Raw 16.0.0.1677.

I notice that DNG images converted from Canon CR2 RAWs using either Camera Raw 16 or DNG Coverter 15.3 with compatibilty set to Camera Raw 15.3 or later will not cooperate with Exif Tool (Phil Harvey). 

I occasionally use this tool to write missing lens serial number data to DNGs but it will no longer work and generates an error message (which disappears without giving one a chance to read it!). Its works fine with DNGs converted with compatibilty set to Camera Raw 14.0 or later however.

Has the DNG specification changed very recently? Perhaps Exif Tool requires updating?