What format did you rip the CDs to?
You should go back to the first PC and check that the tags are actually stored in the files using the Tag Dump section of the tag Window. If the tags are in the files, the second PC should have picked them up. Even with the limited tagging in WAV files, if they were ripped with MC on the first PC they should be read successfully by MC on the second PC.
Oh wait, what specific version of MC are you using?
23.0.96 (1/24/2018)
9. Fixed: Cover art wasn't getting embedded into ripped files.
23.0.94 (1/12/2018)
10. Fixed: File tagging following CD ripping wasn't working.
I know you said the lastest, but that varies based on which update channel you are using.
The deleted folder.jpg files is weird. I embed Cover Art rather than use a side file, where I can, so I can only guess as to what was happening. But as there were bugs in this area, maybe they also caused this issue. Perhaps update to MC23.0.102 (the latest at the top of the board) and rip another CD, or re-rip one, to see if it works as expected.
If so, and the files on the first PC do have tags in the library, then you can just "Update Tags from Library" on the first PC and those tags should appear on the second PC when you run Auto Import again (if "Update for external changes" is set). You only need to use the "Fill Properties from filename" if the files on the first PC don't have tags, and in that case, run the "Fill Properties from filename" on the first PC and then Auto Import on the second.
If Cover Art still appears on the first PC then it could be recovered in a similar way. With the "Cover Art > Audio Mode" set to "in the same folder as the file (as Folder.jpg)", then you can select the problem audio files, right click and run "Save Cover Art To External Location Specified In Options" and "Folder.jpg" Cover Art files will be saved next to the audio files. Test a few first and check. It worked for me.
If the first PC no longer has Cover Art because of the bug above, you will need to run "Get from internet" again of course.