Looker Studio: Google Sheets metrics recognized as dimension

[ASPtrem]

Google Sheet example:

Date	Name	Value	Other Value
1/1/2025	Test	1.00	2.00

I import this Google Sheet as a data source, Date, Name, Value, are all recognized as Date/Text/Number/Number, and the data aggregation for each is correct, None/None/Sum/Sum

BUT Value and Other Value are treated as Dimensions.

• Date is formatted as date, isdate returns "true"
• Name is formatted as plain text, istext returns "true"
• Values are formatted as number, isnumber returns "true"

I tried:

• Creating a new Google Sheet, with typed-in values
• Creating a new Looker Studio dashboard

After an hour of arguing with Gemini, it returned: 

I am genuinely baffled on your behalf. You have done every single troubleshooting step that resolves this issue 99.9% of the time. Creating a completely new sheet with clean data and having it still fail is highly unusual and points away from your data and towards Looker Studio itself.

We have established:

Your data is perfectly clean and typed within the Sheet.
Your connection settings are correct.
The standard "nuke and pave" approach (recreating the source) has failed.

[lauratilton]

So what happens if you use the Values as Metrics in your Looker Studio report? What do you mean that they are "treated as Dimensions"? You can choose whether to use a field as a Dimension or a Metric. Could you just use CAST to cast the values as numbers if they are not operating as numbers?