Hi @Mihail,
My apologies for not getting back with you quicker - I was waiting to reply once I had followed your instructions, and once I had performed more test on other platforms.
My main concern really isn't about Ubuntu, I'm simply trying to test this issue on as many different platforms as I can to build context (I now realize that because Linux isn't officially supported that that information won't be enough to signify misbehavior).
In light of that and in order to further test this issue, I got my hands on an Apple computer with the OS & Spotify versions listed in the next post (otherwise this post will be flagged as spam). On this machine I tested adding songs from a playlist to the library in bulk (no more than 20 at a time in this case). Unfortunately the songs were added to the library in again a seemingly random order that did not reflect the order of the playlist. This happened despite being on a different physical computer and with different account.
On my own machine, I followed the instructions you referenced (to the letter) that guided me through how to perform a clean installation of Spotify from the Microsoft Store. However this too unfortunately yielded the same results (albeit a different mixed up order). I even searched my entire hard drive for any remnant files of a previous Spotify installation, but to of no avail. I even searched the registry, but still the songs weren't added in the playlist order when I added them to my library.
After following the instructions exactly, I still get the songs added in a mixed up order .
After all of this, I'm actually rather surprised that @Eni wasn't able to replicate the behavior I'm seeing on the platforms and accounts that I've tested. I would like to verify that you all are seeing what I am expecting to be the proper behavior:
when you add multiple songs from a playlist to your library they should be added in the playlist order (meaning that song number one at the top of the playlist would appear at the top of your library once it's added, then song number two in the playlist would be listed second in your library and so on).
This behavior is particularly crucial because you can't reorder songs in your library; also there is no practical workaround solution if you're trying to add a sizable playlist to your library while maintaining the order of said playlist.
Also, I'd prefer not to create a new account as I'm the plan manager of the family plan with my family (and not sure how much hassle that would be to switch over). I've already tried to see if I get the same behavior with different accounts, and have verified that all the accounts I try work in the same incorrect and unpredictable manner - because of this, I didn't think it was necessary to create a new account for further testing.
Let me know if there's anything else I can do to aid in the investigation of this issue - I'd love to resolve it.