I know there have been some changes to the pickers. Not saying for better or worse, but there were changes. I haven’t fully read up or explored what changed yet. I believe that all changed at least a couple weeks ago.
I’m not quite sure if the original pickers were a Glide design or something else, but I’m pretty sure Glide may have reverted to using the native browser based pickers to maintain consistency and familiarity for the end user and what they are used to on their particular device and browser. A user will see the same date picker regardless of which website they use, whether it’s a Glide app or something else. However, the style of the picker depends on the browser and device. Apparent if you look at some examples, especially on different devices. It may not seem consistent when testing with different devices, but to the average user it should feel natural and familiar with what they have always seen as a picker on various websites with their particular device, provided those websites are using the standard spec and not something custom.