Based on given feedback I've gotten from a user I've investigated some saving issues that were occurring in Unity 2019.
Any issues that came up during the investigation have also been addressed.

Change log:

• Fixed racing condition during saving, which corrupted some saveables (saveable got destroyed partly before it could save).
• Fixed counting issue with saving, where it would load the same ID for a newly saved instance.
• Saving now saves a proper JSON file that you can edit with the text editor.
• Fixed sound issue that happens when entering main menu and exiting, where it would overlap each time you enter the main menu)
• Included small fix for seeds disappearing when reloading the scene.