Cover album not showing on mobile and tablets


I have one issue with mp3 tag. I did tagging on some songs upload it on client's website. It works fine on desktop and laptops. For tablets and smart phones it's not working properly. Sometimes on few songs showing album art properly , sometimes not.

So please tell me proper configuration and settings to do tags on songs which will perfectly works on any devices. I am waiting for replies. Our client site URL is given below. Please check it online and troubleshoot this problem asap.

Edit: removed URL

All songs tagged from MP3 tag application by me.​ Currently i'm using v2.81.

And what is the difference between those files that do show and those that don't?

No difference between files. All files are in mp3 format.Still i'm confused whats the exact issue?
Did you download songs from given link. Do you saw album art on it?

Please help anyone its dead time work for me.
Otherwise please some one tell me the exact whole procedure step by step. I will do it all again as per your suggestions !

I am afraid that I can hardly do anything about your schedule.

Also, I will not download complete files from a site where I cannot determine the ownership of the files.

But there are things that you can do on your own.

You should look at the files and check:
is the cover actually embedded: you can filter for files that have no covers with
%_covers% MISSING

What kind of tag versions are in the files? Only ID3V2 or others as well?
Are the files OK? Check this with mp3val and MP3diags.

If all this shows nothing suspicious, then it could still be the player. Some have restrictions in respect to maximum dimensions or byte size. Some require special files per folder.

is it necessary to fill all the meta data? Can you tell me configuration so i can do setting as per to check mp3val,mp3diags & ID3V2?? I'm new user for mp3 tag so don't have exact idea about it.

The forum is about the program MP3tag, not tagging MP3s in general.
But here is some general advice:
Determine your use-case.
Find out which metadata is required for this use-case.
Get the information.
Read the MP3tag help, esp. about the tag panel.
Use MP3tag to transfer the information into the files.
See if the result matches your requirements.

I outlined some steps for trouble shooting. So try these first or get acquainted with the basic principles of MP3tag first.

OK, here is one:
If you want to get the same album name and artist name into all the files of an album, proceed as follows:
Load the files into MP3tag.
Select the files in the files list.
Enter the artist name in the tag panel.
Enter the album name in the tag panel.
Press Ctrl-S to save the modification.