I use a shared library in my Photos app. When I upload photos from my library to a shared album, the timestamp changes. The order of the photos is random. How can I upload photos from a shared library in the Photos app to a shared album while retaining the original timestamp?
I don't use Shared Albums, but my understanding is that pictures there are copied with lower resolution and without their metadata intact. They're meant for sharing with strangers, I guess. It's cool that, even though they are new pictures (and thus have new dates) they don't count against your iCloud storage.
Another option, that I use, is the iCloud Photos Link:
Share photos and videos with an iCloud Link on iCloud.com - Apple Support
The link stays up for 30 days, and people can download the images to their own computers during that time. They have correct dates, and they are full resolution, but they don't have captions or locations. Unlike Shared Albums, they don't invite comments. The links can be used by anybody, even if they don't have iCloud. A downside may be that, if you send the link to someone, they can send it to anyone they want. Of course, you can cancel the link at any time.
Anyway, that's what I do.
Wrong timestamp iCloud Photos in shared Album
