Dimmer buzzing, lights flickering
If the converter has a wide input range like 85~265Vac then it is intended to be CC over all international voltage tolerances and not dimmable without stress and noise.  This input range is 265/85 = 3.1

If the converter has a reduced input range with CC like 185~265Vac with a Max/min ratio of 1.4 then it will start to dim when the input is below 185 and less likely to be over-stressed by pulse currents pinging the coils and surge currents on caps.  But this is no guarantee they designed it correctly for dimming, but may advertise as such. ( cheap on Ebay)