@noris Here is the second part of the tests you asked for.
Playing local content from MacMini Core via wifi to Node 2 (with the latest firmware installed)
Started playing on April 24 at 9am. First track: “You’ll Have to Swing It” by Ella Fitzgerald. During this two-day test, local content played almost flawlessly. I noticed stopping/skipping two times.
After 323 tracks (approximately 24 hours playback time), the first glitch: playing stopped during “Blop Down” by Cozy Cole Orchestra (after 65%).
On April 25 at 11:55 am local time, I restarted the next track in the queue (“Songs (5) of Ophelia, for voice & piano, WoO posth. 22”).
Twenty tracks further, “'81” by Joanna Newsom, skipped completely (April 25, around 13:20 local time).
After that, playback continued without issues for almost 22 hours. I stopped the test on April 26 at 10:48 am (during the track “Night in Tunesia” by Yusef Lateef Quintet).
There seems to have been nothing wrong with the two tracks during which the stopping/skipping occurred. On April 25 around 2 pm, I “added next” to the queue both tracks. They played flawlessly.
Please let me know if you need further testing or information from my side. I would be happy to help. As you can see in the first two tests, this is not just about an occasional glitch. And as you can also see, it is clearly neither caused by wifi, nor by the Node 2. I hope that solving this problem will get the full attention of the support crew. Especially since, over the weekend, I again saw several new posts and comments of users experiencing similar problems.
Results of a third part of my test (with Qobuz content) is here: Playback Skipped - #24 by Francois_De_Heel