Old lossy DNGs no longer working with Adobe software

In 2018 I shot photos with my iPhone and a Fujifilm X-100F in RAW. I converted them to lossy DNGs in Lightroom. They have since been living in Apple Photos (as RAW + JPEG pairs).

Now, I was looking to re-edit them with Lightroom to export them in HDR, and renewed my license to do so. I see that the iPhone RAW files do not show up in Lightroom (the X-100F files do). I tried converting them with the latest DNG coverter, but that refused to read the files..

I then read about the update to the lossy DNG format (moving from JPEG to JXL compression) and thought that might be the culprit. I found that the older version 13.0 of the DNG converter can read these files, and used that to export them to linear DNGs (by forcing compitability with Camera Raw 2.4). But Lightroom still cannot read the files. I noticed that Topaz Photo AI can read the files once linearized, which provides an (extremely convoluted way) to get to most of the data.

Is this known? Are there ways to "upgrade" old DNG files? This is super close to data loss and not appreciated.