''Click to call'' functionality in Eloqua

I am experiencing some issues with ''click to call'' functionality- i.e. the functionality that allows you to place a call from a mobile device by clicking on a number. This seems to be working only on iphone devices and not Android. Apparently the issue is caused by the fact the we enabled external tracking in Eloqua for all campaigns. My understanding is that for all the hyperlinks the external utm parameters will get appended automatically. So, the mobile number is getting appended with junk digits. Is there any way that this could be fixed?