It would be interesting if you could check if when you are not moving you are connected to 5ghz band.
If the inspeccion was done on 2.4ghz which it happens A LOT in my country that could be the issue... you get disconnected from 5ghz and then it reconnect to a 2.4ghz band....
To seamsless roaming you need to have a site survey doneno 5ghz not in 2.4ghz.
This would explain your temporary lost in the video.
Just as a review in WLAN.
2.4ghz has more range but it has less usable channels(3 usable channels)
5ghz has less range, less noise, but more channels(23 usables channels)
So whenever you do a site survey for a dual band dual radio APS you need to do it on 5ghz.
It would be nice that if you had a Fluke air checker or something similar, if you could check the range of the 5ghz band, to see if it well covered, to roam.
Cheers
Carlos