Custom content provider drag only image url in cms 12

Hi Team,

   I have create the custom media tab and binding all the folders and images from external json file. As a editor when I am dragging any images from custom tab into the page . It's taking the tab reference. Suppose I dragged a image which url is  https://my domain/cms/images/2RhY61HO4Jx8hdD9R7ecbE/?scale=2k .

In the page property value is displaying like  /en/customdam/https://my domain/cms/images/2RhY61HO4Jx8hdD9R7ecbE/?scale=2k.

Another biggest Issue- When external json file is getting refreshed and if json file desn't contains the old images then page property data is also getting lost.

I am looking for a solution. Please help..!