I have encountered a bug within the Google Analytics Data API (GA4) related to event filtering using the DimensionFilter.
Specifically, when applying a filter to events that include the full-width characters "（" and ” " in their names, the returned data set is unexpectedly empty.
In contrast, filtering by events with their equivalent half-width characters "(" and " " yields the correct data.
For this issue, I utilized the FilterExpression as detailed in the API documentation: FilterExpression Documentation.
Additionally, I attempted to replicate the output using the GA4 API's Query Explorer, which resulted in the same issue (image_1).
It's worth noting that the presence of data for these events is confirmed via the Google Analytics 4 admin interface (image_2).
Reproduction
- Metrics: eventCount
- Dimensions: deviceCategory, eventName
- DimensionFilter: eventName → "（" or " "