On iOS27 on iPhone 16 Pro Max (using a more recent Testflight build), I was initially able to reproduce this from the long-press on app icon > Take photo, although Lightroom was also syncing at the same time, which may or may not be related. There was no error, it just opened straight to Lightroom Grid view and pressing the blue camera button didn’t do anything.
Once I force quit the app, the control center button, lock screen widget, long-press on the icon and blue camera button all work again for me. So for anyone else affected, try swiping up to the app switcher and then swipe the LR app off the top of the screen then try reopening it and visiting the camera.
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