On the April 2020 version of Desktop, downloaded the Gateway Performance PBI template file and pointed it to my gateway logs.
In the query editor, both the "QueryExecutionReport" query and the "DataError" query both error with the following:
DataFormat.Error: There were more columns in the result than expected.
The problem appears after the Table.ExpandRecordColumn step - in the QueryExecutionReport I get it when I try to do the Table.Group step (I repeated the action in the UI to see if that had change) and in DataError the problem also occurs after the Table.ExpendRecordColumn step, but when you try to filter the rows for where the expanded JSON equals true.
Works correctly in : Version: 2.79.5768.663 64-bit (March 2020)
Doesn't work in : Version: 2.80.5803.1061 64-bit (April 2020)