I just finished setting up a 128gb MicroSD card as internal storage for my Samsung device. However, I tried to copy files from the back up I made for the SD card on to my phone but now my PC shows neither the internal or external storages when I plug in the phone. I'm assuming that the reason is that I made an SD card as internal storage and the PC can no longer recognize the file format or device type or something like that. Is there a way to make it so I can still transfer files to either the internal or external without making the SD card portable. Or are there any services or apps that I can install besides a cloud service (like Drive or Dropbox) to wirelessly transfer the files on?
Firstly, this shouldn't happen. Android's MTP is designed in such a way that it will handle any and every kind of internal memory structure your device has. Maybe your drivers are having an issue, it should show internal memory in your PC regardless of being portable mode or not.
Nonetheless, you can use apps like Airdroid or ShareIt to transfer files over your local wireless network. Just connect both devices on same WiFi and follow the instructions in the app. Airdroid is easier to use with less hassle and doesn't require you to install anything on your PC.