It’s not uncommon for people to be able to put out higher power outdoors for a number of reasons, but generally speaking you should test in as similar conditions as possible to the environment you’re training in- so the higher number from your race might work better for outdoor workouts if those are of interest to you, but by the same token if your current ‘indoor’ FTP has you working at what you feel is an appropriate level of difficulty then I’d stick with that.