I think that the origin issue is https://github.com/handsontable/handsontable/issues/2667, as autoColumnSize plugin controls the widths of columns. In this case it ‘thinks’ that the data wrapped to the 2nd row, which is not true.
I will add your case to the internal ticketing system for this issue and update you upon fix.
The only workaround I see is to use colWidths to fix the width of the columns, but then you would need to specify the width for all of them. You can alter the widths via updateSettings() if needed but the need to set width for every column might be a limitation (it all depends on your project requirements).