I’m having similar issues but I think I may have tracked it down to a NTP refresh interval which may be lengthy interval. In other words, your clock doesn’t refresh every few seconds and likely updates every few minutes/hours since it’s not something that needs to be regularly adjusted once it’s set. When I change my time zone within the options the device time displays the proper offset (-7 in my case for Mountain Time US) but the previous time is still displayed. I left it and came back to it the next morning and the proper time was displayed (well, not proper since I had left it at -5 30 as I was experimenting) so my guess is that when you adjust the offset to NTP (only way to adjust the time) you have to wait until the device polls the NTP for time, applies your offset and adjusts local time. I have nothing to confirm this yet as I just set it to the proper (for me) offset and am waiting to see if my theory proves accurate. So, you may try setting your proper offset and giving it some time. I agree this isn’t the most attractive way to address this but if this is indeed the case it should set itself properly on the next refresh/poll. Perhaps Ray can chime in on what this interval is set at and if my guess is accurate. Adding an option to manually set the time or even using PC time (I have several items set to poll the PC for current time which I prefer since you have one less port open to the public, one less device polling an outside source that has potential to become a way into the network) would be a good way to give more flexibility for end users or possibly have it poll immediately after making a change to reflect the proper time instantly would resolve such issues.
Just thinking out loud I guess and hoping someone with more knowledge on inner workings can chime in since I just received mine.