Before I get crucified by the LDAC Mob for my blasphemy. I have access to both LDAC and Aptx Lossless. I can tell the difference in detail retrieval between both as I am only 32 years old. Not saying I have golden ears but am not that age as stated by some of you. And I understand that one's own hearing deteariates as one gets older. To me LDAC sounds awesome but not as lossless like some claim or just go by Sony's word. I have multiple high end TWS, gaming earbuds and an expensive Audeze Euclid. So have some experience with comparing them.
I never said you don't hear the difference.
The difference is unrelated to LDAC. Whatever makes the difference, its not the codec.
It is imposible, for any human on this planet, to hear the difference between an 990kbps LDAC connection and an 1200kbps aptX connection.
In blind tests, people can't even distinguish 320kbps MP3 from 1411kbps WAV files.
You would need the best ears any human ever had and even if there is an difference, its would be around 0.5db and less. You would need to have years of experience as an mastering engineer to hear that.
Whatever causes this difference in sound for you, is not the codec, its something else. Maybe the headphones or your smartphone use a difference processing, maybe a different EQ, whatever.
But whatever it is, even if there would be an difference between LDAC and aptX Lossless, just take it as granted and LDAC really isn't lossless, you would never ever, not in 1000 years, capable in hearing so.
You would need an perfectly tuned multi-way multi-ba Earphone and reference tracks that are good enough to highlight that to be able to tell an difference.
And no, non of your earphones is even remotely good enough to highlight the difference. You would need at least something like the IER-M9, TG335, VE8, Mach 80 or something similar to be able to hear the difference.
But i doubt that even an trained professional could hear the difference with one of these