Remove “instance_id” from permalink? please…

Hi,
Is there any way to remove the “instance_id” variable from permalink URL?
In my case it causes a slow load of the event page simply because this variable is parsed in the url …
I also think it is a serious problem for seo because it causes duplication in urls.

You can check the speed difference between the url without variable :
http://rift-valley.com/viaje/safari-kiboko-uganda-febrero-2017/

and with:
http://rift-valley.com/viaje/safari-kiboko-uganda-febrero-2017/?instance_id=20

Refresh for better results,

Thanks for your support.