Probably too late to be useful but I just stumbled across this post which concerns problems I've encountered with new aluminium-framed windows and doors that were fitted to my place in 2107.
Apologies in advance for the rambling post!
Our alloy framed, triple-glazed windows have an WER band B rating according to a sticker on the frame (Band A+[etc] is the best insulated). Since October 2010, all new windows must be WER band C as a minimum - so yours should be at least that too. Ask the supplier.
In my opinion, it would be very difficult - if not impossible - to manufacture an aluminium-framed window with thermal insulating properties approaching the best modern plastic-framed windows. Those of us who choose alloy window and door frames for the cleaner sight-lines, security, longevity and strength have to accept the thermal insulation hit. So alloy frames will always be more prone to internal condensation than the best insulated plastic frames - doesn't mean to say it's inevitable though. It's all about the dew point of water (i.e. the point at which water vapour condenses as liquid. There are dew point charts that show at which temperature and air humidity this will occur so it's predictable.
Before I purchased my new alloy-framed windows and doors, I tried to find out if frame condensation would be an issue. It was a frustrating experience. I even asked a question on this forum. The universal response was that condensation would only occur if the room air humidity was "too high". Strictly speaking, this is only half the picture.
The window inner frame temperature is just as important in determining the dew point. And anyway, what is the optimum room humidity level for a domestic property? Turns out that's a million dollar question. Depends on what reports you read. In late 2016, when I looked into this, anything from 30% to 60% relative humidity is mentioned as an optimum range.
I purchased a humidity meter. In a room where the floor was screeded in July 2017, the humidity level was typically in the 50 to 65% range over the 2017/18 winter - because the floor wasn't completely dried out. We suffered condensation on the internal bottom ledges of both a sliding door and a floor-to-ceiling window (i.e. only on surfaces very close to the new floor level) - and it was worse than the example shown in your video. This past winter, humidity levels have been lower on average, I'd say 35 to 55%, and condensation has been minimal but not completely absent. Like your window, our sliding door does not have a trickle vent (due to my error) and that's where a little condensation formed but only on the coldest days. In the same room, our tall windows have a trickle vent and I don't remember seeing any condensation this past winter (though I live in the South and it wasn't a particularly cold winter).
Either you can increase the temperature of the inner window frame surface (other than increasing room air temperature, it's difficult to image how to do this without serious surgery) or reduce room humidity. I'd suggest getting a humidity meter and a thermal temperature 'gun' - I use both. Compare the temperature of the problematic inner window frame with another in the house that doesn't give the condensation problem. Also, check room humidities. Without a trickle vent and with no open windows, overnight humidity in a bedroom will likely be too high, in my limited experience. Get the humidity in the bedroom to 50% -ish and you may minimise the condensation problem.