You are using an old version of Lightroom, CC 2015 (also known as version 6), which is not compatible with your OS.
So strange things can happen, like the Info overlay displaying with a white instead of transparent background.
There's no way to fix this, but you can hide the overlay by pressing the I key on your keyboard once or twice.
Also note that if you uninstall LR CC 2015, you won't be able to reinstall it, since it uses a 32-bit installer.
The latest Mac operating systems will only accept 64-bit installers.
Since you seem to be having a Creative Cloud subscription, I suggest that you upgrade to the latest version of Lightroom Classic, 11.2. See the system requirements here: