Strange non-ending Notification on my Galaxy S20FE 5G

[djc290761]

Yesterday evening my Galaxy S20FE 5G started sounding a a non-ending regular repeating tone.

This tone has a frequency of around 3 tones every 5 seconds.

The tone sound like "ding-*****" where the ding is shorter than the *****.

Putting the phone into vibrate simply replaces the tone by a vibration.

When the phone is put into silent mode the vibration is still emiited.

I have tried turning all apps to "no notifications" but this has no effect on the erent tone.

I can still send and receive calls and messages, browse the web etc. Apart from the annoying tone it seems to have no effect on the phone

The phone is running Android 13 and is in the O2 UK network.

Is there ant cure for this bizare behaviour?

If not how can I repair/reset operating system without a factory reset.

Strangely enough my Galaxy Tab S6 Lite recently hung up, whilst updating, and I had to do a factory reset. I am not too keen on repearting the procedure with the S20.

Many thanks

[AndrewL]

@djc290761: Next time you hear the unidentified tone, please swipe up from your Home screen and head to Settings > Notifications > Recently sent. If you can see any app listed here that corresponds with the sound you're hearing, then tap on the app, and adjust your notification sound options from here e.g. Deliver quietly, or toggle notifications off completely. Let me know if this helps. 

[djc290761]

Thanks for you help but I lost patience, got fed up. did a factory reset and rebuit the phone using my Samsung account and everything worked OK ----- including the annoying noise.

So I did another factory reset and rebuit the phone from scratch and now the noise has gone.

i am now keeping my fingers crossed.