Some dimmers are quite touchy / flaky in the lower part of their range.
My Mom has a dimmer “light switch” controlling a dimmable flood bulb (CFL, I think) in her dining room ceiling. If one turns it down to the bottom part of its range, any incoming voltage fluctuation turns it off, and it can only be reset by switching it all the way off, then back on (the control has a rotary “dim” function and a push on - push off function). This is interesting because slowly turning the light all the way down with the dim function does not create that need to “reboot”. So far as I can tell, heat is also not the problem. But, “who knows”...
Well, now that you’ve made me think, I realize that I’ve never had a lamp of any kind that was ‘dimmable’, before this Ikea thing.
I’ve had some lamps that were ‘3-way’; but never one that dims.
And I haven’t used the 3-way lamps in years - they’re in storage, and I never used anything with them but 3-way incandescents.
But, how are THEY going to work with LEDs, when I pull them out now?
(Jeez; life has become so complicated...)
I hadn’t considered voltage fluctuation, such as a drop from other appliances kicking on. This would probably affect these dimmers more so.
But everything electrical creates heat as the juice passes through the parts. Maybe only slightly but they do heat up a bit. Anytime you have a mechanical connection such as the dimmer switch to the electronics inside there is a chance for heat to slightly affect the variables and tolerances to affect the resistance slightly.
I used to run into this with motor controllers quite a bit, and a motor speed control is basically a dimmer switch, a potentiometer. Sometimes they would have to be readjusted once after warming up then they would stay stable after. :)