If you rotate the symbol without entering it, it will only modify the 'instance' of the symbol you're working with. So:
- Entering a symbol (you see a purple bar) modifies all instances
- Outside of a symbol, your positioning, scale, and rotation will only affect the single instance of the symbol (no purple bar)
If you have a single symbol you want to split into two separate symbols, you can 'duplicate' a symbol by selecting it in the resource library, and clicking 'Duplicate Symbol' at the bottom.