I thought this was using SDKs embedded in apps and advertising platforms. This is a different threat model. You need to block ads and prefer using websites instead of apps which have more access to device info like the advertising ID.

If you’ve got an Android, go to Settings, search for ads, and find the advertising ID and delete the ID. It’s a stable identifier that can be used to identify your phone.

Switch to more private browsers like Firefox for Mobile and install uBlock Origin.

EDIT: I’m not saying this will protect you against IMSI catchers or tower based drag nets. In addition to not bringing your phone, when you do go home you need an entirely different set of tools to protect yourself.

Are those networks marked as hidden SSID networks? Hidden networks require the client STA to broadcast them to find them.