To do the trial I would not import all photos.
What OS are you using? Are you importing from disk? Do you copy you Photos to some other location? How are your Photos organized (current situation)?
I am using 10.11.5. Photos are not that organized. They are all stored currently on my hard drive. And the import was a bit wonky to say the least. pictures got assigned new dates (some even in 2021 which is impressive)
If Lightroom can't handle all my photos then not sure why I would switch to it and pay a monthly fee. So I guess I wanted to import them all to see how it performs.
Thanks for any help you can provide.
I have a bunch of photos that I imported for test purposes that show 2017. that was the wrong date setting of the camera. LR just reads the dates.
I have on my external USB 3 drive 23k+ photos (2+ years of photos), on my 6Tb internal drive in my HO 10+ years of photos (I don't know the exact number now), some of them are even scanned pictures of the 90th. I even do not experience any lag in performance when using LR. LR can handle a lot of pictures.
I had a lot of pictures before switching from DPP and Bridge/ACR to LR. I cannot remember a hassle during the import of the pictures. But my pictures were organized per date. I'm still adding keywords, running face recognition etc on them, to be able to use search functions, but for the rest all went well.
You did not answer, if you copied the pictures to a new location during the import, or if you kept the pictures at their current location.
Unfortunately I'm not using OS X, so I can't really help you with OS related problems in connection with LR.
What I suggest: Import first a smaller part of your pictures and play with the LR features to get you used to the program. Then import the rest. LR avoids duplicate imports, so your database will not be messed up by using this.
Concerning your initial problem, are you sure, that you do not have a recursive directory structure. At least by using symbolic links on a UNIX system, this may be possible.