I tested that back when it was first reported on the Beta thread and could not reproduce the anomaly. I just tested it again and couldn’t reproduce it.
I have smooth playback through every minute rollover (with one exception… See 
last paragraph).
Since the point at which you experience that anomaly is the exact time when the in app player is stitching together two adjacent one minute video files from within the same date folder on the card, it would lead me to believe that you are experiencing some sort of buffering delay in the player getting the next file. Possible causes: slow read capability on the digital card reader in the cam, slow read access speed on the SD card itself, slow P2P WiFi transfer speed to your device (distance, intereference, congestion, router QOS throttling), slow processing capability on the player device.
Troubleshooting I would do to isolate the cause would be to test it on multiple cams running the ẞFW with multiple variables: (1) at their current location and moved very close to the router; (2) testing them each individually at each location with no other devices on the 2.4GHz network and with full network load; (3) test with current SD card and a new UHS3 V30 HE uSD; (4) test on multiple viewer devices.
EDIT:
Additionally, with the timeline in it’s default scale, it advances to the left at the top of each minute. Another test I would do is to expand the timeline to it’s limit so that you can see it advancing with every second and see if it reproduces the affect, ruling out an app player issue. I would also be sure to be running the latest app PR. I would also pull the card and read it on a player\scrubber to see if it is something embedded in the recorded file metadata or if it is occuring as a result of the read\transmit\play process. If it occurs there, I would test the same on a new UHS3 V30 HE uSD for comparison.
Exception from above 
: A glitch has been reported by @SirDom and confirmed by @carverofchoice that causes the playback to skip over the first minute of each hour when the player is stitching together the last one minute video file from that hour into the first video file of the next hour in the next indexed folder. The video file for that minute is still there and can be played, it just gets skipped by the in app player. This doesn’t happen when playing from the last minute if a day to the first minute of the next.