@haimr,
It was not clear to me how many approximate playing hours you have on your X1. I have more DACs than good sense. They all present music a bit differently but I really like the X1. In my experience, the X1 needs substantial playing time to settle in. In my system I found at 200 hours the unit was consistently better, and even more so at 400 hour mark.
The X1 is a streaming DAC and is not configured to accept digital inputs from a CD transport or player.
It also was not clear to me if you are using the Lumin App to access Tidal or perhaps using in conjunction with a server and player like Roon? If the latter, what do you use to serve Roon Core? I do not utilize Tidal, but do use Qobuz. I find sound presentation is somewhat more transparent with Lumin App, but I often use Roon for the broadly developed landscape options and convenience.
You indicate you have a Plinius preamp--a well regarded company. You can experiment with the X1 going directly to your amp, bypassing the Plinius, by using Leedh Processing option with the X1. I have used my X1 with preamps and also with Leedh, which really is very good.
Best