Why does my Apple Watch keep switching to silent mode

Perhaps you are inadvertently activating "Silent" Mode because of it's top row location in the Control Center.

Try to Rearrange Control Center

1. Touch and hold the bottom of the watch face, then swipe up to open Control Center.
2. Scroll to the bottom of the screen. 
3. Tap Edit to make the buttons jiggle.
4. Touch and hold a button until it turns white, then drag it to a new location.
5. When you’re finished, tap Done or press the Digital Crown.

Hello JessDanielson,

Thank you for reaching out to Apple Support Communities, and we'll be happy to help in any way we can. We understand you're having issues with your watch going into silent mode. To start, is the Cover to Mute setting on? This article goes over the feature and how it is used:Change the audio and notification settings on your Apple Watch - Apple Support

"Cover to Mute setting is on: On your iPhone, open the Apple Watch app, go to the My Watch tab, then tap Sounds & Haptics."

You can also follow these steps to see if it improves:

Restart the Apple Watch and iPhone:

Restart your Apple Watch - Apple Support

Restart your iPhone - Apple Support

We hope this helps.

Cheers!