Okay - Thanks Dejan for the messages. I understand now.
There’s an issue whereby if the prime coincides with the finish line of the event it is often not accurate. This has been the case for a long time (to the extent that I’ll never run a prime that coincides with the finish line, but use finish line banner FAL instead).
Both spots are in exactly the same position. If you’re looking to validate FAL on last sprint, use the finish line time.