Image showing as question mark after loading from SQLite database

I'm trying to save an image that a user will upload into an SQLite database, and will be able to view it as a card. The problem is, when I load the image from the database it shows up as a question mark.

This is the code to save the image into the database:

     public void SaveCard()
     {
         Texture2D newTex = new Texture2D(IMG_source.sprite.texture.width, IMG_source.sprite.texture.height);
         TXT2D_cardArt = IMG_source.sprite.texture;
         byte[] bytes = TXT2D_cardArt.GetRawTextureData();
 
         newTex.LoadImage(bytes, false);
         newTex.Apply();
 
         byte[] newByte = newTex.EncodeToPNG();
 
         string base64Str = Convert.ToBase64String(newByte);
 
         string sqlString =
             "INSERT INTO " + dbName +
             "(CardName, CardDescription, CardImage)" +
             "VALUES (?, ?, ?)";
 
         dbManager.Execute(sqlString, IF_cardName.text, IF_cardDesc.text, base64Str);
 
         IF_cardName.text = "";
         IF_cardDesc.text = "";
         IMG_source.sprite = null;
     }
 

And this is the code I'm using to view the card, but it's not the final code. It's just used to test if the card will be shown successfully:

     public void ViewCard()
     {
         string sqlString = "SELECT * FROM " + dbName;
         List<DeckORM> deckContents = dbManager.Query<DeckORM>(sqlString);
 
         foreach (DeckORM dorm in deckContents)
         {
             byte[] bytes = Convert.FromBase64String(dorm.CardImage);
 
             IF_cardName.text = dorm.CardName;
             IF_cardDesc.text = dorm.CardDescription;
 
             Texture2D tex = new Texture2D(IMG_show.sprite.texture.width, IMG_show.sprite.texture.height);
 
             tex.LoadImage(bytes);
             tex.Apply();
 
             IMG_show.sprite = Sprite.Create(tex, new Rect(0, 0, tex.width, tex.height), new Vector2(0, 0), 100);
         }
     }