Cambridge Audio - Melomania A100

I got the Cambridge Audio A100 earbuds a few days ago. The sound is great, but the ANC seems very unstable. I want to know if it's just an issue with my pair, or if others are experiencing the same thing. When ANC is set to "high", the noise isolation is very good, and the background noise can become very quiet. But when I'm listening to music on the street, the ANC sometimes suddenly cuts out or weakens significantly. The music keeps playing, but the background noise becomes clearly audible. This situation lasts for one to a few seconds, then it returns to normal ANC. The problem occurs particularly frequently when I'm walking on noisy or crowded streets. The problem is particularly severe when ANC is set to "high". I tried turning off ANC adaptive and dynamEQ, but it seems to make no difference. When ANC is set to "medium", the weakening of ANC still happens, but it's more tolerable because the volume is closer to the original remaining background noise. Does anyone else have similar problems?

Cambridge Melomania A100? But dunno what is the price like in your country, in UK is £119. Best in terms of Audio Quality, lots of codecs (LDAC, aptX Adaptive, lossless, and more), great ANC, and decent battery life. 

Cambridge audio melomania are astounding for quality, I absolutely love my pair and their ANC are very good too

Cambridge audio melomania, absolutely adore my pair

Cambridge Audio - Melomania. Both the in ear buds and over ear, are fantastic bits of kit

I own the cambridge Melanomania too The Nothing ears are far bassier. Easier to remain in your ears and just easier to use.

But the Cambridge are really heavy. So theyre likely to fall out more regardless of the fit.