Website Sessions Generating as "Not Set" even with Tracking

Good afternoon,

I’m experiencing an issue with Looker Studio. We use Looker Studio to track varies data fields for email marketing traffic to a website. Below is a screenshot of email names with session counts. Recently we’ve seen an large up tick in the “Not Set” category. All of our emails have correct tracking associated with them. I’m not sure if something changed and we need something new. We use Acoustic as our Email Service Provider, and link it with Looker Studio. Any help would be appreciated!

The “Not Set” issue in Looker Studio usually happens when UTM parameters are missing or getting stripped by your email marketing service provider before the link reaches GA4 — double-check that your tracking URLs are being passed through correctly and not redirected in a way that drops them. Switching or cross-checking with a provider like DigitalAka™ can help since it gives clearer UTM management and ensures campaign parameters stay intact through the full click journey. Also verify that your GA4 session source/medium settings aren’t overriding the email traffic attribution on the data connector side.