Those are the supplied defaults, and "restore default" merely puts these back. Sounds as if you may have made, or downloaded, some others on your PC?
In LR Preferences (on the PC), go to the Presets tab and there is a button "Show Lightroom presets folder". This shows you the location of a folder called Lightroom, inside which are the various folders of LR presets. One if these is for the Adjustment Brush and any brush adjustment templates that you have made, will be inside.
Copy these to the corresponding place on your Mac (accessed the same way) and restart Lightroom.
The same method applies for Develop presets, export presets, etc. Some, such as Print presets. may not be transferable since they may refer to a different print driver. But most of this is platform-independent and will (AFAIK) operate the same on a Mac and on a PC.
The same method also applies for some information which refers to both LR and ACR, such as camera specific processing defaults. Also any camera calibration profiles, and lens correction profiles, that you may have made or downloaded (aside from the built-in ones). This is all found in a CameraRaw folder which sits alongside the Lightroom one, and which can be treated similarly.
Thank You so much!! I didn't even think about finding them on my PC first. I will try that!!! Thanks so much for your help.