EXIFTool fails to write metadata when a Warning is encountered

[StudioPetrikas]

Hello,
I'm trying to learn the ins and outs of this great tool, however I'm struggling in a few places.

Earlier in 2025 I was able to grab all metadata from a RAW file and write everything to a JPG file.

So, an output JPG metadata would look like this:

For some reason, I am no longer able to do that. Exiftool throws an error and does not write anything to any file I open. Here's an example of a said error:

Warning: Tag 'FocalLengthIn35mmFilm' is not defined

(repeat to infinity for every tag that's not in a handful of tags available for JPG)

I have tried suppressing these errors with -m argument to no avail.

Weirdly, the original Exiftool documentaiton states:

The information type isn't supported by the format of the target file.
Warnings are NOT generated when a tag isn't written because it is normal that many tags can't be written when copying between files of different formats.

I'm losing my mind over this. It seems my code hasn't changed, but I'm no longer able to write the dumped EXIF information
The exiftool became really sensitive to any mismatches of exif data and throws an error (and writes nothing) for every minute issue.

I'm hoping I'm missing something very obvious, and kind of hoping there was a change to either zeroperl of the exiftool itself that might have prompted these issues to arise?

I didn't want to raise an issue, because it seems that this is a fault in my understanding.
Looking for any advice, thank you very much in advance!