Haven't had time to thoroughly test this, but I seem to have a "new" problem with 6.0.1.8 and the UI3 links sent with Pushover alerts: they now don't open the exact clip I'm expecting, but rather some more or less random (but within the same hour) time from the correct camera. It may be from roughly a minute behind the expected time/clip, up to a half hour or so beforehand. Very bizarre, but for now I'm going to roll back to 6.0.1.7 to see if it goes back to normal.
Edit: Yes, moving back to 6.0.1.7 fixed this completely, even for the exact same (older, recorded with 6.0.1.8) clips that wouldn't link correctly from UI3 Pushover alerts under 6.0.1.8.