Unable to get songs onto my phone without breaking them

All of them are in mp3 format and are perfectly playable on my PC. Here are the ways I tried. 1. Connect both devices via USB. File transfer is enabled, I can see the filesystem of my phone on my PC. The copying process always stops midway, even when I tried to copy one song by one song. 2. I took out the micro SD from my phone and put it in the PC which has an micro SD slot. Copying works?, but destination files are all broken and unplayable. 3. I went to the place where I originally downloaded the songs onto my PC, which hosted them as an rar archive on Google Drive. I tried to download the archive directly to my phone, but the archive disappears from my phone's filesystem after the download is done. What is happening to my phone? It's a Asus Zenfone 5 running on Android pie. The micro SD card is about 7 years old. Edit: I tried a few more things after posting the question initially: 1. Checking the filesystem of the micro SD card on Windows 10 reveals no errors. 2. Using FTP inbuilt on my phone, I can copy the rar archive from my PC to my phone's internal storage. After that I tried copying it to the micro SD card with a file manager on my phone. After the copying process is done, the archive is no where to be found on the micro SD card. It seems like the problem is not my phone, but the micro SD card making the files disappear after copying the files onto it.