I have two separate Node-RED projects (not to be confused with flows) because I track them in two Git repositories.
It seems that every time I open one project, the other one stops working. Is there any way to run both projects simultaneously? I found this package, but I'd prefer to achieve this natively within Node-RED if possible.
No, Node-RED is a single tenet environment, it can only run a single set of flows or project at a time.
If you want to run multiple projects at a time then you need to run multiple instances of Node-RED.