File statistics not showing if someone has viewed a file in Teams, only if viewed in SharePoint

I am not sure if this is more of a SharePoint issue than a Teams but this seems like a good place to start.

My org communicates things to staff through a weekly newsletter that is posted in the "full staff" Teams channel. In the post each week, we prompt staff to react with a specific emoji once they have read through the document.

Lately, we've had an issue with multiple staff members saying they didn't know something that was in the memo so we are trying to figure out if it's because they're not reading it or they're just not retaining it.

I have the SharePoint site set to track who is viewing the file. I Just went in to the stats for this week's and it's only showing 23 individual viewers. I noticed that one person I KNOW has opened/read it wasn't on this list. She has files set to view in Teams, not to open in browser so I asked her to click "open in SharePoint" to see if it added her name to the view list - and it did.

So it appears that who is viewing a file is only tracked if it's opened in SharePoint, and if it's accessed through Teams, they don't appear as having read it. **Is there any way to change this?** I've looked at the file stats through Teams and it didn't increase the amount of viewers, until the one tester opened it in SharePoint.

Google said that there is a Teams Insight app that pulls together this data but the only one that comes up is Viva Insights, which I don't think is correct. I do not/wouldn't be able to get admin rights to run the audit feature.