What does Garmin CIRQA firmware 2.50 fix?

Garmin’s changelog only says “improvements to OHR,” with no further detail. The most likely target is the optical sensor dropout bugs reported on Garmin Forums and Reddit, rather than the interval-response accuracy lag found in this site’s own testing.

Does firmware 2.50 fix CIRQA's heart rate lag during interval training?

Probably not. That’s a sensor-and-algorithm issue tied to fast changes in effort, found in a single testing session rather than widely reported by other users, which makes it a lower priority for a one-line stability patch.

Why does CIRQA's heart rate sensor stop working after charging?

This is an unresolved, widely reported bug. The optical sensor stops responding after charging and doesn’t resume until the band is powered off in the Garmin Connect app and back on via the button, even though it shows as connected and synced.

How do I check what firmware version my Garmin CIRQA is running?

Open the device settings for CIRQA in Garmin Connect and look for the software or firmware version listed there. Updates roll out gradually, so not every unit receives 2.50 at the same time.