You can see current production firmware build (i.e., what non-Beta users are on) here: https://help.sense.com/hc/en-us/articles/115011311187-What-is-the-latest-monitor-firmware-. If you’re not in the Beta group and your firmware differs from this (and it has been at least a couple of days after that firmware was released), then please reach out to support@sense.com.
If you are in the Beta group (if you’re not sure if you are, just ask), your firmware version might differ from this and may not even be in sequential order. That does not signify a problem. When you join the Beta group, you agree to run test builds. These test builds originate from different source code and thus are versioned differently. If you’d prefer to no longer receive test builds, let me know and I can remove you from the Beta group.
There is no way to manually update or revert your firmware, and such a feature is not planned.