Confirmed here. I reckon that the problem is caused by overlapping notes. And the overlapping notes are caused by misinterpretation (or non-interpretation) of the tempo changes during the imported MIDI clip.
Here are some problematic C2 notes in Reaper (with some transposed to show the overlaps:
And here they are in energyXT(with alternate notes selected to distinguish them):
And finally, here is the view in the Arranger when opening (pink notes) / closing (blue-green notes)the in-line Editor:
I do hope that this is enough info for the bug to be fixed.