Ah. That is due to unity spontaneously deciding to change the save path on Mac.
The game save files were originally kept in this location on Mac: '~/Library/Application Support/com.Company.ProductName'
But the latest version of unity changed it to the one used on Windows which is: '~/Library/Application Support/com.NecroBunnyStudios.RiseoftheWhiteFlower'
You would have to copy the files from the first location into the second one. But frankly, you can also just hold the S key to skip all text. Using that you should be able to get to chapter 6 in just a few minutes.