Incomplete data input due to merged cells with raw files

Dear friends,

I have data source (I can't change) containing tables as Excel with 2 first rows are merged into group column and the data set is below those 2 lines. My problem is that seems like Power Query might interpret the first two merged rows as headers or as a single block of data, leaving the rest unrecognized.

The issue seems to be happened with only raw file where no changes has been made. If I edit anything or just even re-save the file, the issue is gone. It's quite confusing to me on how to deal with this. I have like 20 files so open and save is still doable but I want a way to work around.

If anyone experience the same issue, please help me.

Thanks and regards,