I had lost hope to see any firmware updates for the Dericam range but there's one now available for M801W (and also M202/203/204/205/206). Very little change but still good to take...The files can be found in the Download Center of the Dericam web site.
System: 0.37.2.46 (this system file is also valid for M202/203/204/205/206)
Web UI: 8.1.1.5 (this Web UI file is only for M801W, each model use a specific Web UI file)
The only change documented in the release note is the addition of the No-IP DDNS support.
Usual recommendations:
Do not update through WiFi, use the RJ45 connection.
Update the System firmware first, and then the Web UI file.
Do not power off before completion