LRCC - Why is File Size Greatly Reduced upon Export?

I recently started using the cloud based version of LRCC on my desktop computer with Windows 10.  When I export photos after editing, the size of the file is crazy small.  Even if I'm not cropping the image. 

For instance, a raw image that is 27 mb is 429 kb after export in jpeg format, with only some basic edits and no cropping. 

The export settings I'm using are:

File Type: JPG. 

Dimensions: Full Size. 

Quality: 90%. 

Including all metadata. 

Output Sharpening: Screen. 

Amount: Standard. 

Color Space: sRGB.  

I've tried playing around with the export settings, even reducing the quality to 60%, but with no success.  

I upload my images to a website that requires the images to be a minimum of 3 mb, so this is a problem for me. 

Thank you in advance for any insights and help you can offer me!