samsung s9

I have a Samsung S9 bought in 2021 (refurbished). I'm in the Netherlands. I have never used it in another country so far. I'm planning to go to Thailand soon and therefore already inserted a Thai SIM card (that I still had from a few years ago) into the SIM 2 slot. After restarting the phone it...

Every time I try to transfer new music via USB onto the SD card in the phone from my windows computers, It goes through the motions of the files transferring over, but the music either partially plays or doesn't at all. When I restart the phone, those new files are just gone. It's a 128 GB...