Re: Pixel 6 Android 12 - disconnects from network voices
When speaking aloud, you also need to disable battery optimization for Google TTS voices, or as the product is named now, "Speech Services by Google". Please open Android system settings - Apps - See all apps - find and press Speech Services by Google - press "Mobile data and WiFi", then enable both "Background data" option and "Unrestricted data usage". Then go back one step and press "Battery" and change from "Optimized" to "Unrestricted". Now go back to home screen and try listening again with screen off. Does this help?
I don't use Google voices at all. It's not practical to use online voices, and their offline voices are low quality and have no questioning intonation. My preferred choice are Vocalizer TTS voices, and occasionally Acapela TTS voices. Both available in Google Play, apps for free, voices for purchase. With Vocalizer though you may try each voice for free for one week.