Can third-party apps mess with heart rate readings on Charge 5? (Zombie Diary 2 crash issue)

[modhellooo]

Hi everyone,

First-time poster here. I recently ran into a weird issue with my Fitbit Charge 5 and I'm not sure if it's just me or if anyone else has noticed something similar. Hoping someone can help me debug it or at least point me in the right direction.

**The situation:**
I’ve been experimenting with a few lightweight 2D games on my Android phone to test how they affect battery drain during background fitness tracking. One of the games I tried — an older one called *Zombie Diary 2* — consistently causes my Fitbit to stop recording heart rate in the background while the game is running.

I’m **not sure if this is coincidence** or maybe there’s some low-level interference happening (e.g. phone enters battery-saving mode or blocks Bluetooth sync). Interestingly, when I force close the game, Fitbit syncs again and HR data resumes as normal.

**Steps I've tried so far:**
- Verified Bluetooth connection is stable (used Spotify & calls in parallel, no issues)
- Tried keeping the Fitbit app locked in memory ("Don't optimize battery usage")
- Installed and tested on both Android 12 and Android 13 (same behavior)
- Tried a few other casual games — no problem with those

This isn't about the game itself, more about **whether certain apps can indirectly impact how Fitbit collects or syncs data** in the background. I'm curious if anyone here has ever run into a situation where an unrelated app causes data gaps or sync pauses?

TL;DR
Is it possible that a background process from a third-party app (like a 2D mobile game) can interfere with Fitbit's HR tracking or syncing via Bluetooth?

Any advice on what else I could check would be a huge help.
Thanks in advance!

P.S. I’ve saved the full log & test screenshots in a doc in case anyone wants to take a deeper look. Happy to share that once the post is approved so I don’t clutter the thread.

[Rich_Laue]

I don't understand what you have written has to do with the recorded heart rate. 

Your heart rate is recorded by the tracker on the wrist, not your phone. Which has nothing to do with the recording of the heart rate. .