If your reports or data sources aren't showing all the information you expect, check the following:
Missing data in reports
Is the data cached?
If the report is missing some recently added data, you can refresh the cache by editing your report and in the upper right, clicking 
Is the data filtered?
Edit the report, then click Resources > Manage Added Filters to see if there are any filter properties in the report. If there are, check their setup to make sure that's not the cause of the missing data.
Missing fields in data sources
Is the data source out of sync with the data set?
If the data source is missing some recently added fields (columns), you can add them by editing the data source, then in the lower left, clicking REFRESH FIELDS. Learn more.
Is your Google Sheets data source missing rows or column?
If the rows (data) or columns (fields) of your Sheets data source are still not appearing after refreshing the fields as described above, make sure the data source connection includes the proper range and options. You must be the owner of the data source to do this.
- Edit the data source.
- On the left, click EDIT CONNECTION.
- Review the connection options, on the right. Be sure any specified range includes all your data, and that you are including hidden and filtered fields, if appropriate.
Sheets connector options.
Is it a connector limitation?
Connectors based on fixed schemas, which includes many of the Google product connectors, may not deliver all the fields of the underlying data set. If your data source appears to be missing fields that you know are in the original product, it's possible that field is not supported in Looker Studio. You can check the issue tracker to see if the field has already been requested, or if not, file a feature request.