Audio file transfer issue from computer to phone

Hello,

I am stuck with a problem transferring audio files to my smartphone (Xiaomi Redmi Note 8 Pro).
To summarize my issue: When I try to copy my music to the main storage space of my phone, some files refuse to be copied. The "file transfer" mode is activated, and I can copy most of my music. But only a few won't transfer... I don't think it's a cable issue since I performed a reset, and before that, I could copy ALL my music (I communicated this problem to my dealer; he advised me to reset the device).
I recently sent him an email with a video showing what is happening.
Here is the email:

"Good evening, as mentioned in my previous email, I am sending you the video illustrating my problem with transferring only certain audio files to my phone.

Explanation of my video: It is important to specify that this problem only affects the shared internal storage space of the phone, not the SD card.
-[0:00-0:07]: I indicate that the phone is indeed activated in "File Transfer" mode.
-[0:08-0:22]: I quickly show the contents of my two storage spaces on the phone ("Shared Internal Storage" and "SD Card") and then the folder where I want to copy my audio files.
-[0:23-0:27]: I navigate to the folder on my computer containing the audio files of interest.
-[0:28-1:17]: I copy (the ones that are willing to...) the audio files into the destination folder I am interested in (that at the end of step 2). It can be observed, despite the audio lag, that some songs do not copy and halt the process.
-[1:18-1:40]: I show in the copied folders that certain audio files are not present.
-[1:41-4:05]: I copy the same folders to the SD card to prove that the problem only affects the "Shared Internal Storage." (from 2:00 to 4:05, it is the transfer of a complete folder to the SD card without errors).
-[4:06-end]: I copy into the "Shared Internal Storage" the folders that were completely copied to the SD card. And it is again possible to see the termination of the procedure due to certain audio files that cannot be transferred.

That is my problem. It is impossible for me to copy these audio files to the Shared Internal Storage (which bothers me a bit since I am particularly interested in them...).
I prefer to copy them to this storage space rather than to the SD card because I do not have much space on the SD card (I prefer to keep it for photographs). And since I have a huge amount of audio files, I prefer to store and organize them all together in one place for simplified use, namely the Shared Internal Storage. Furthermore, after the reset (which caused this problem), I absolutely need to put all my audio files (present before the restoration, including these) back in the same path as before. This allows me to restore my music player application with all the playlists filled as before (I cannot see myself filling them again with the number of audio files I have...).

That’s all; I think I have explained what I could about this problem. If you need more details, do not hesitate.

I wish you a good evening,
(signature)"

Since I can't upload the video online on this site, if you would like me to send it to you, you can give me your email address.

Please don't hesitate to ask for more information about my problem if I am not clear or if any information is missing.

Good evening to you, and I hope someone can help me!

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