Welcome to Hubitat!
A small UPS for the Hubitat Hub is really a best practice to ensure it can run smoothly through power blips/outages. It does not have a built-in battery backed up RTC, thus it needs to be able to access the Internet to set its clock. Unfortunately, if the Hubitat hub is up and running before your DHCP server and Internet connection is up, it seems to get itself into trouble with respect to automatically correcting its time.
My advice to you is to send your 'feature request' to support@hubitat.com to make sure this issue stays on their list.
I have my Hubitat hub, cable modem, and router all on an APC UPS. This has completely avoided this issue for me. Also, since the hub is really a full computer, running everything locally including a relational database, losing power can result in corruption of its internal database. The hub can usually detect this, and will restore a recent automatic internal database backup. However, if you had added new devices and automations that same day, those changes might be lost as the automatic backup occurs at ~2am each day. Make sure you manually download a Hub database backup after making significant changes.
