My wifi is saying that the security is weak so it’s not working very well

Check with the service folks at the Chevy dealer to see if there are adjustments and settings that will beef up the Wi-Fi security.

Not an iPhone issue here. The iPhone can only receive as much security as the Wi-Fi in the Tahoe can deliver.

This is just a warning that your WiFi network may be more susceptible to hackers than a more secure network.

Here’s the support article on things that could cause this warning:

Recommended settings for Wi-Fi routers and access points - Apple Support

Also, if you tap the info button next to the WiFi network:

It might reveal more information on what is causing this.