This one will be really short.
I see a lot of people still guessing when their order was cancelled by CS and whether or not it was a chargeback. And a lot of people guessing by checking if their buyer’s profile is still active.
But it’s much simpler than that.
If you received a message saying “ORDER CANCELLED BY BUYER” then it means that your buyer initiated a chargeback with PayPal or through their bank. In this case you will receive 2 emails back to back to your associated email address.
In most cases like this fiverr support might be able to get your funds back. And it seems that know they are doing that automatically almost right away after a chargeback if you delivered everything as promised.
If you received a message saying “ORDER CANCELLED BY CUSTOMER SUPPORT”. Then, well, it’s obvious that your buyer reached out to fiverr support and they cancelled your order because you didn’t fulfil one of the requirements or didn’t deliver your gig as promised. (But of course there are always exceptions and sometimes orders cancelled by CS mistakenly)