canon – Picture looking sharp in Live View mode, then losing sharpness after picture has being taken

Since recently I am experiencing an issue with the sharpness of my images.

I am using canon 70D with a macro lens for shooting jewellery and I need to have a very clear picture to capture the brilliance of the crystals. That’s why I am using a tripod, I am using tethering between computer and camera and I shoot from the software program basically – my camera is as still as it gets when taking a photo.

What happens is that the crystals of the jewellery look sharp when I am looking at Live View mode and then when I look at the picture after it has been shot sharpness is lost to a certain extend.

This is how the image looks before taking the picture (in live view mode):
https://imgur.com/9nSD7W1

This is how it looks afterwards:
https://i.imgur.com/xubtioq

I took these pictures with my smartphone capturing the screen of the camera. If you look closely you will see the difference. It won’t be noticeable in daily life pictures I suppose, but for my job, it is an issue.

Does anybody have an idea what is the problem here ? I recently upgraded the firmware to 1.1.3 (canon 70D), of course, that shouldn’t be an issue, but I figured I will mention it.

Thank you!