You can't just copy things from one SD card to another when it comes to apps. They must be installed onto the phone and moved to the card, or installed onto the card directly. Anything else won't work. You can only use a SD card that is within the size (storage amount) that works for your device.
And, if the SD card was converted to be "Internal" rather than "External" storage, so that you could put apps on it, then it would have been encoded. Making accessing the data impossible without it being the original card in the original device and without any changes.
At this point, you are going to have to save any files (not apps) you had/have on the card(s) somewhere else (say a computer) and clear the card completely. Restart the phone (power it off and back on, without the card in it. Once it is back on insert the card and see if you can change the card to be "Internal" storage. I will include instructions below. If it allows the change, then you will have to redownload any apps you wanted on the card and reinstall them. Then move the files you saved elsewhere back to the phone or card as well.
First, you need to be using a phone that is running at least Android "Marshmallow" (6.0) or newer, or be able to upgrade to it. Second, you will need the instructions I am including below. And third, you need a phone that has not been restricted by the manufacturer from making this change. Which does happen.
NOTE: If any of the steps are missing on your phone, or they don't work for you, then you have a phone that either has an older Android version or has been restricted by the manufacturer. If that is the case, you will not be able to use this information.
How to turn the "External" SD card into "Internal" storage - Option A
Please be sure you start with a blank SD card. It needs to be blank because when the card is converted to "Internal" storage, it will be formatted (wiped) and encoded (making the cards data only readable by that device).
- Go to device “Settings”, then select “Storage”.
- Select your "SD Card", then tap the “three-dot menu“ (top-right), now select “Settings” from in there.
- Now select “Format as internal”, and then “Erase & Format”.
- Your SD Card will now be formatted as internal storage.
- Reboot your phone.
If you don't reboot the phone, many things may not work correctly, so make sure you do.
How to turn the "External" SD card into "Internal" storage - Option B
Be sure you start with a blank SD card. When the card is converted to "Internal" storage, it will be formatted (wiped) and encoded (making the cards data only readable by that device), so anything on it prior would be gone.
- Go to "Settings", and then select "Storage & USB".
- At the bottom of the list you should see the SD card's details, including the option to format it and make it "Internal" storage.
- Once this is done, reboot the device and you can start running things from the card.
If you don't reboot the phone, some things may not work correctly, so make sure you do the reboot.
An Additional Note:
Some apps (like system ones) are not movable. So while you can move downloaded ones, and some of the system ones, you will not be able to move many preinstalled apps.
A Final Note:
If you set up the card as "Internal" storage, then the data on it will not be readable by any other device. To access the data you would have to connect he phone to say a computer and copy it over to the computer from the phone/card. Otherwise only phone can read the data. Also, be sure you do not reset (hard or factory) the phone. If you do, then all the data on the card will no longer be readable, even by the phone itself.