Processing DNG from DJI Phantom Drone = curvy horizon

Just curious, processing DNG files from a DJI Phantom Drone with a straight horizon the output from SNS-HDR results in a curvy line.
Could it be that there are some hidden parameters inside the DNG to correct the lens that didn't got processed in SND-HDR.
As a workaround a can pre-process the files in Lightroom - here i get a straight horizon - and import 16bit tiff in SNS-HDR. Or I correct the horizon from the SNS-HDR output later on in PTGui.
DNG file in Lightroom and HDR output from DNG files imported in SNS-HDR
[attachment=0]2018-03-27_090853.jpg[/attachment]
Could it be that there are some hidden parameters inside the DNG to correct the lens that didn't got processed in SND-HDR.
As a workaround a can pre-process the files in Lightroom - here i get a straight horizon - and import 16bit tiff in SNS-HDR. Or I correct the horizon from the SNS-HDR output later on in PTGui.
DNG file in Lightroom and HDR output from DNG files imported in SNS-HDR
[attachment=0]2018-03-27_090853.jpg[/attachment]