Not Receiving Group Texts and Server Alarms on WiFi

When I'm connected to WiFi, I am not receiving group texts that include one Android user. Additionally, I'm not receiving web-based texts (such as server alarm notifications) when there is an issue. However, when I disable WiFi and switch to cellular data, I receive all of these messages immediately.

My carrier is T-Mobile.

I've tried basic troubleshooting, but the issue persists. Any advice on resolving this so that I can receive all messages over WiFi would be appreciated. ¡Gracias!