Will Google figure out your other web activity if running everything through a vpn?

Questions
1

I’m using Google Messages and running all my phone traffic though a vpn. Would Google somehow know when it’s me opening up an app since it happens on the same ip and same device at around the same time every day?
I’m on GrapheneOS but I also use Calyx.

If I wanted to exclude Google Messages from vpn traffic, should I also exclude other apps like Carrier Services?
Thanks I’m a newb.

2

yes they can
Remeber our nightmare: Fingerprinting
Figure out? That I can’t comment but can they is a yes

3

IP address is just one identifier and cellphones have multiple identifiers. If you are sending that message with an unique identifier attached to a known identity like a cellular number, then you are not anonymous.