Where are you selecting the file and which version of MMA are you using.
I see an expansion icon for Playlists with nested Playlist allow to select nested Playlists.

MMA build 1290 running Google Pixel 9A running Android 16 syncing to MMW 2024.1.0.3113

I have nested playlists. Under the main header of Xmas I have Xmas Rock or Xmas Pop etc.
When adding a song to nested playlists I see a problem.
Select track -> Select Add to playlist -> Xmas.... I do not get to the nested playlists. Instead it treats that as a playlist and adds it and goes back to the playing que view.
For it to work I must hit the 3 horizontal bars on the right. Then my sub playlists show up and I can add it to the one I want. There is no confirmation it just adds.
In MMW if I hover over the Top name in a second it opens the nest and allows me to drop the file where I want. If using the menu send to it is automatically shown.
Could the bars be elongated to make it easier to grab with one handed use?

I consider this an annoyance rather than a minor bug.

MM is the only database. 53K files @ 644GB and growing