Have done lots of searching but haven't found much. It is intermittent and unpredictable as far as I can tell. Unable to determine if there is a trigger or not. Any ideas?
https://postimg.cc/V5WLFfq5
https://i.postimg.cc/ZY1B400P/hrt.png
[url=https://postimg.cc/V5WLFfq5][img]https://i.postimg.cc/V5WLFfq5/hrt.png[/img][/url]