Loudness normalization is a new feature that Tidal added only a few weeks ago, and annoyingly they turned it on by default. I'm sure that they added the feature only because Spotify has it. Just like they copied Spotify's autoplay feature (Tidal's version doesn't work very well and they also turned on by default). Every time the Tidal app gets updated, remember to go check your settings. Some settings have been getting reset, such as the streaming quality getting reset to the lowest level.