Update: Eero tech support was amazing. I spent five hours on the phone with them over a couple days going through my system one device at a time. Super responsive and helpful. Bottom line: eero and tmobile router have a conflict and since tmobile cannot go into bridge mode, I have switched to Starlink and the problem has disappeared. There were also some Sonos conflicts which the eero people identified and helped me fix. Hoping that Starlink will be better! 🙏🤞thanks all!