That issue means that NSO is not finding the strings file, meaning you didn't copy it to the correct path or at all.
You obviously copied over the lclassics.titlesdb file. And likely the games xtx.z's. I'd assume the sfrom too, as you probably copied over the entire 01008D300C50C000/romfs folder. So... how its not finding the 01008D300C50C000/romfs/bootapp/resources/strings/<language>/strings.lng... My only guess is you are not using the same locale on your switch as you are in CaVE. CaVE defaults to English.
That does not explain the other issue though.
Maybe theres a mismatch between the roms file name and what the database entry is trying to load? S-5988_e.sfrom vs 5988_e.sfrom? There was a change to the standard rom name format in some recent version. It's possible I tried updating CaVE, missed something, and didn't think much about it to remember it at all.
Im really reaching here though. I don't have a clue what it is, if you have truly eliminated the full unlock patch, sfromsig, correct sfrom format, and the console restart. Normally the issue is found far before all of these are checked off. Most of the time its the unlock patch not being placed correctly, or the wrong one installed. Next most common is the console restart being needed. Then its someone selecting the SNESClassic sfrom format by mistake. I have seen an issue with the sfromsig like once. Heck, usually before it gets that far, the person figures out on their own that they didn't do one of the first things correctly, but said they did.
