Your days in 1SE for Android suddenly say "No media available for this day on your device", even though the photos and videos are right there in your gallery? On Android 14 and later, this happens when 1SE has limited access to your photos instead of full access.
Why limited access empties your days
When Android asks how much of your library 1SE can see, Allow limited access hands over only the photos and videos you pick in that moment. 1SE treats that as permission granted, so nothing looks wrong, but every day whose media you didn't pick comes up empty. Checking that "permissions are allowed" won't reveal it, because limited access counts as allowed.
Give 1SE access to your whole library
This replaces limited access with full access:
Open your phone's Settings > Apps > 1SE > Permissions.
Tap Photos and videos.
Choose Always allow all—some Android versions call it Allow all.
Go back to 1SE and open a day that looked empty: its photos and videos are listed again. If a day is still empty, nothing in your library was taken on that date.