So I was having the same problem with my traffic not updating and I emailed Tesla about a week ago. After a couple emails back and forth I was told this morning that since the last update that will traffic will no longer update unless you input a destination address into the navigation. That can't be right, can it??? That would be ridiculous. In case you think I am making this up, here is a screenshot of the email.
It would be ridiculous (I suppose not impossible). But as a counterpoint, consider that the answer you got directly contradicts what someone else heard upthread:
Traffic colors wrong in some zoom levels / not refreshing
So...???...
Bruce.