First, try disabling the GPU. Under Preferences > Performance, uncheck Use graphics processor.
If this doesn't help, try resetting the preferences.
Hold down Option+Shift while launching Lightroom, click yes in the confirmation dialog.
Thanks for your answer. Both options didn't make a difference.
Since you're on a Mac, it might be necessary to restart the computer for the resetting of preferences to take effect.
I restarted the computer, nothing has changed about the issues I had before.
I also have noticed that there is a problem with the metadata, they are not correct.