silent mode automatic

Does it look like this? This is the ring/silent switch I mentioned above on the side of your iPhone, How to put your iPhone on vibrate, ring, or silent mode - Apple Support.

If your iPhone is turning this on and off automatically there is either something stuck in it, stuck in the middle, and/or an issue with your iPhone. I would suggest doing a hard restart. If that doesn't fix the issue, you may need to bring it in for a Genius Bar Appointment - Genius Bar Reservation and Apple Support Options - Apple

If you don't have any Focus modes setup the only other silencer is on the side of your iPhone - How to put your iPhone on vibrate, ring, or silent mode - Apple Support.

Are certain notifications being silenced? We could walk through the steps to verify those aren't silenced within the Notifications settings.

Hello Natasha2329,

It sounds like you're either using Smart Activation with Focus modes or have them turn off / on at certain times of the day.

1. Open Settings
2. Tap on Focus
3. Tap on the Focus mode automatically turning on

Towards the bottom there is a Set a Schedule section. You'll want to ensure the schedule meets your needs if using a time-based approach.

Smart Activation is your iPhone learning from your habits (locations, app usage, and more). Say you always go into a coffee shop and turn on Do Not Disturb and turn it off when you leave. Well if you have Smart Activation on, iPhone learns from this behavior and starts to do it for you so that you no longer have to.

I hope this helps! If I didn't answer your question or having something else related to this topic please let me know!