Okay, but it's an issue with your configuration/set-up/hardware/software. You repeatedly made it sound as if the Priority Device feature isn't used to select a profile. That's why
@Noixd thought "[they don't] have their keys connected to separate profiles"
Tesla:
"You can link a driver profile to a key (or keys) to allow Model Y to automatically select the correct driver profile when the linked key is detected as you approach the vehicle and open the driver's door."
The complaints I've seen aren't that this never works (i.e. profiles are selected at random) but that sometimes it selects the wrong profile. We've never had that problem although to be fair we no longer have our phones "paired", we just added them as phone keys.