We continue to work on the widgets, but after doing a lot of digging and reading through a lot of documentation our lead developer has concluded that this is because Android no longer allows us to sync the system clock via services (which is what most of the widgets use). Basically, on those widgets now using the system clock, the app itself must perform the updates, rather than just showing you what is on your device clock.
The 5x1 clock widget is the only one currently that passes through the system clock (not using a 1Weather service), and from what we've seen, it should stay up to date.
The newer 5x1 clock widget should work correctly, as it's the only widget that we have right now that uses the system clock - which is necessary to keep the app updated on Android 7 (Nougat) and 8 (Oreo).
We are working on updating the other widgets to use the same technology.