Quick answer: Toggle the UI off (disable the overlay canvas or its root) when entering photo mode and capture, then restore it on exit, rather than relying on camera culling masks.
Your photo mode gives a free camera and DOF, but the health bar and minimap are baked into every screenshot. Screen-space overlay UI composites on top of all cameras, so culling masks do not hide it; you must disable the UI explicitly.
How to fix it
1. Disable the UI root on enter
When photo mode starts, deactivate the HUD canvas (or set its GameObject inactive). Screen-space overlay UI is not affected by the camera's culling mask, so toggling layers will not hide it.
2. Capture without overlay UI
Take the screenshot while the UI is hidden. If you use a render texture, render only the game camera into it so no overlay canvas is composited in.
3. Restore state on exit
Re-enable exactly what you disabled when leaving photo mode, tracking prior active states so you do not turn on UI that was already hidden for another reason.
4. Keep photo-mode controls on a separate canvas
Put the photo-mode UI (camera, DOF sliders) on its own canvas you can keep visible while the gameplay HUD is hidden, so controls do not appear in the shot either.
Catching the ones you can't reproduce
The hardest version of this to fix is the one you can't reproduce — it only happens on a player's hardware, OS, driver, or save state, under conditions that simply aren't present on your machine. A report that says “it crashed” or “it froze” gives you nothing to act on, so the bug survives release after release while quietly costing you players.
Automatic error capture closes that gap. Each failure arrives with its full stack trace, the device and OS, the build number, and a breadcrumb trail of what the player did right before it broke, so even a failure you have never seen becomes a specific, reproducible issue. Fold identical failures into one signature ranked by how many players each hits, and your worklist sorts itself worst-first instead of arriving as a stream of vague complaints.
This is where a tool like Bugnet earns its place. Its SDK captures every Unity error automatically with the full stack trace plus device, OS, memory, build, and game-state context, folds duplicates into one grouped issue with an occurrence count, and ties each to the build it first appeared on — so you fix the problem that hurts the most players first and confirm it is gone when its signature disappears from the next release.
Ship the fix, watch the signature disappear from the next build. That's how you know it's really gone.