Originally posted by jatrax Lens name is not supplied by the lens but rather by the software. The lens will supply an ID code that must be read by the software and used to look up the entry in it's database. I suspect your software has not been updated to include the new 55-300 PLM yet.
To test that try some other software such as Irfanview or Faststone, both are free.
That’s exactly the problem. What version MacOS are you running? If you’ve got High Sierra and you’re not seeing the lens name, then Apple hasn’t added it to Photos, yet. I think, however, that it was actually added in one of the Sierra updates. I’m not sure which it is because I use LightRoom and ON1 on my Mac and haven’t looked at Photos recently. I’d recommend updating your OS version.
Edit: OK, I checked Sierra (updated to the latest), which I'm currently running, and it's not there. If Apple has added that lens to Photos, it must have been done in High Sierra and you'll need to update to that version in order to get it. Since I'm not running High Sierra, yet, I can't tell if it's there, and there doesn't seem to be a support document that lists all of the lenses included.