here is a picture of the issue incase I did not explain it good enough. as you notice track 1 is playing on the right and what is playing is the sounds of christmas. but if you not on the left it is showing Hallelujah which is not playing.
By default, audio files added to WMP should play according to the sorting in Windows Explorer, which seems a bit strange.
Maybe you can try the sorting feature here.
Edit:
If you're using just the Integra DTR-40.3 for playback, you may need to compare the ID3 tags of the audio files to identify the pattern of how the Integra DTR-40.3 plays them. It could be the Track tag.
Edit2: (Sorry, you can ignore the ones with strikethroughs. My mind was a bit muddled in the evening.)
Well, I've looked at your picture again carefully, and I realize I misunderstood earlier. The browser's built-in translation had some issues. You might be saying that the album cover displayed for the currently playing song is different from the original album cover.
Okay, I took some time to test it, and based on my tests, sorting the filenames with 01, 02, 03... should work without any issues in WMP and some apps that support MiniDLNA (like BubbleUPnP in my case). I think this might be an issue with how the Integra DTR-40.3 plays them. You could try editing the ID3 tags.
It’s best to go to the MiniDLNA Settings page and click 'Rescan' after making the changes.
When they are not sorted:
As a comparison, I sorted a portion of them:
As for the album cover issue, since these are songs from the same album, the cover is the same for all of them. If you want to change it, you can use some ID3 tag editing tools to modify the cover.