Big Clive did a you tube video
https://www.youtube.com/watch?v=fWh2obSY0dQ in it he goes through the problems with the LED bulb, mainly related to dimming them, but he goes though the different designs.
A LED is a current dependent device, and our homes are supplied with a set voltage 207 - 253 volt, with 230 volt being the nominal voltage, so we have to use a device to change from constant voltage to constant current, the easy way is the capacitor, it is cheap, and does not produce much heat, but we can also use pulse width modulated chips, and these need a minimum voltage to work, I fitted an S9 LED to replace a halogen tube, which stated it would work from 95 to 250 volt, others have a much narrower band.
Also the lamp can produce transiences on the supply, using a tungsten lamp can damp these out, my wife had a 5 bulb chandelier using G9 bulbs, it would flicker unless one bulb was a quartz bulb, and we were using expensive bulbs, however we in the end found a bulb which did not allow us to fit covers, but did not shimmer when on, and I know this is due to a large smoothing capacitor inside them.
The problem is there is nothing in the bulbs description to say how it works, and one bulb with smoothing can result in rest also stopping their annoying flicker.
This room had 3 GU10 bulbs, and to stop flicker needed to swap bulbs around with kitchen also with GU10, then son fitted a pendent lamp in this room as well as the GU10's and problem went away.
This [attachment=1]20220603_113820_small.jpg[/attachment] bulb is clearly complex, with loads of smoothing capacitors, it was until it failed a colour changing zigbee GU10, I would think if one or two of the lights were of this type, likely others would stop their flicker, but just a guess, a surge protection device may help, and any other type of filter, but there is no magic cure, personally I don't like down lights, my floor is dark, so reflects very little light, as spot lights the GU10 works well, lighting corners of the room where light would normally not reach, and in high ceilings they work reasonably well, my sons house kitchen has a very high ceiling seen here [attachment=0]102 Kitchen Bike.jpg[/attachment] high enough to walk under a bike hung on the wall.
However that area was lit by a 22 watt LED replacement for a fluorescent tube when I lived there, now it has around 60 watt of lighting, and seems no brighter.
