I have noticed that sometimes the quality differs for example download Björk - Debut album from tidal in lossless is OK download Björk - Debut album from qobuz in lossless is cut off sometimes it is the other way..it is best to always check
It is due to the sample rate. The album master is originally in 48kHz. TIDAL Hi-Fi quality can give you 48kHz but Qobuz CD quality is forced to 44.1kHz, in this case signal above 21kHz will be filtered to avoid under-sampling for old encoder which I guess is what Qobuz using. Qobuz Hi-Res quality shouldn't have this problem as it delivers original sample rate.
TIDAL & Qobuz in 90% cases the cd quality is the same and file size.... only defence is in high resolution Qobuz 1. Blind (Album Version) Qobuz TIDAL 01 - Korn - Blind TIDAL