There are a few things going on which could impact the relationship between MiXplorer and QuickPic but without more detail from your case there would be no way to say they are related.
Could you clarify what you mean by "QuickPic gallery support"?
Specifically what actions result in what error? Log?
I'm not just nagging you to log and provide details for the sake of it. There really is a possible connection between what you are experiencing and and other issues.
Here in the log, original image name is in line 30. And the weird name that QuickPic is showing, is in line 32.