I've been running PRTG for some time now using SFLOWS. Recently it started showing gaps in the SFLOW data where for 1 minute it will reflect rediculously low total volume and speed that I'm certain is not reflective of reality. It doesn't occur on any regular basis, though it rarely goes more than 5 minutes without occurring.
It started after a reboot of the system hosting PRTG. I've tried recreating all my SFLOW sensors, but that has not helped. Restarting the PRTG service does seem to help for a little while, but typically within 30 minutes it starts up again.
Packet captures of the SFLOW data don't show any lulls of any kind occurring on the source side.
Any thoughts on what this could be, or how to troubleshoot it further?