Good Morning @suzannet.1zcgiu,
Thank you for being willing to supply additional context by answering my questions. Now, it’s time for me to offer some context to you.
As you may know, Republic offers multiple coverage options for its newer compatible phones. Republic provisions cellular coverage with one of two network partners. One partner operates a GSM network and is T-Mobile. Republic’s other partner operates a CDMA network and is Sprint. T-Mobile and Sprint have merged, however, the networks remain separate. Cellular coverage is provisioned with one network or the other not both simultaneously.
Additionally, due to its unique nature (sufficiently unique to be patented), Republic’s blended WiFi/cell service requires access to data (WiFi or cell) in order for text messaging to work and also to receive voicemail notifications. Cell data used for these purposes is whitelisted meaning we do not pay for it above and beyond plan cost nor does it count against any cell data purchased as part of one’s plan for Internet access. That said, when away from WiFi (or if one’s work WiFi network is blocking the previously referenced MQTT protocol), cell data must be available.
The “X” you note indicates the cellular tower a phone is connected to is not supplying data likely because it is a roaming tower (a tower owned by a partner of one of Republic’s partners). A Network Settings reset or even merely restarting one’s phone might temporarily “fix” that by changing the tower a phone is connected to.
All of the above said, I believe it would be possible to improve your experience. Doing so would require a change of provisioned coverage on your Pixel 3, which is accomplished by acquiring a different SIM from Republic. How to make that request is linked here:
Your son might benefit from a change of provisioned coverage as well. For more insight on that, we would need to know the brand, model and generation of his phone?