@lovehifi22, What application are you using to access QoBuz? Obviously, if you are using the QoBuz App, it sounds like you need to contact them for assistance for your lost playlists.
If you are not using the QoBuz App, what App are you using? Is it possible this other App is at fault and not QoBuz? Please post your configuration, what hardware you are using and what Apps. Is there any difference between the playlists that get lost and the other playlists that do not? Are they the same size in terms of number of tracks? Anything other difference? Are the playlists getting lost old ones, new ones or random? Please confirm that ALL App software is up to date and current (probably yes, but I have to ask)?
Unfortunately, these types of issues do NOT get solved quickly. BTW, I had an Audiovana issue when my playlist tracks were in the correct sequence and the displayed albums were not. I searched everywhere, checked my settings and called my friends. No one had an answer. I posted the question on Audiovana Community Forum and got an answer very quickly. There was setting that I had to set and it fixed everything. Please do not give up. Please keep us posted. Thanks.