iPhone 17 Pro Messages haptics unreliable, possibly due to Always-On Display?

Hi all - I’m hoping someone from Apple or the community can help confirm whether this is expected behavior or a software bug.

I rely heavily on haptic vibration for notifications since my phone is almost always in silent mode. For several months now, probably since I got the 17 pro in Jan 2026 (upgraded from a 13 mini), the Messages app has been extremely unreliable with vibration alerts, and I’ve missed multiple time‑sensitive texts because of it. Notifications from 3rd party apps vibrate normally - this issue seems isolated to Messages, perhaps other native apps too.

My setup

• iPhone 17 Pro
• iOS 26.4.1 (but have experienced this in earlier versions)
• Silent mode enabled
• No case (to rule out case‑related vibration dampening, as mentioned in this thread.
• Apple Watch is powered off and not worn (to avoid notification forwarding per this article (which itself is an issue, but that's another topic).
• Settings > Accessibility > Touch > Vibration: On
• Settings > Sounds & Haptics > Haptics: Always Play (also tested with "Play in Silent Mode")
• Settings > Sounds & Haptics > Text Tone > Haptics: Accent
• Multiple device restarts

General behavior

• Vibration notifications work perfectly for all third‑party apps.
• They also work for Messages only in certain physical states.

Messages app behavior

• Works: when the phone is face‑up on a table
• Works: when the phone is awake and in use (but not inside the Messages app)
• Does NOT work: when the phone is face‑down
• Does NOT work: when the phone is in a pocket

This makes it extremely easy to miss texts unless the phone is face‑up and idle.

Possible workaround / suspected bug

Out of desperation, I tried disabling Always‑On Display (Settings > Display & Brightness > Always On Display > Off).

After turning AOD off, vibration alerts for Messages suddenly behave normally again - including in pocket and face‑down scenarios!

I'm wondering if iOS is incorrectly treating the Always‑On Display as “active,” and suppressing haptic alerts as if the device were awake... but somehow only for Messages (or possibly other native apps). I'd be hard-pressed to think that this is expected behavior.

This is all empirical observation, so it'd be great to get technical eyes on this to confirm or clarify. Thanks in advance to anyone who can help shed light on this!