Encore Pro data has "dashes" in the line

My Encore Pro data is a solid line most of the time, but lately I have had several days with dashes in it. Like ----------- that. The data is there, but not in the usual solid line. The lines move up and down according to the pressure, etc., but they are not the usual solid line.

I searched for this subject but did not find any info, do any of you have this problem? Most of the time I get it once in a couple of months, but I have had it something like 3 times this week. The data is not unusual, not real high on pressure or large leaks, etc. Just the dashes. Those of you who have followed my problems know I have a lot of them, but why the dashes in the data? Apria was of no help.

Any info appreciated.....Dave

Still using Pro 1.8xx?

Could you post example of what you are seeing and compared to the proper way?