I made a quick sandbox of this issue in my R12 environment and it's having the same issue...Honestly it seems like a bug, so there's probably benefit from raising a support case so that Apptio can address it.
I tried playing around with some possible workarounds but the issue persisted, so the best alternative for now that I can think of might be to create a report identical to the drill so that you can keep the actual drill in place but navigate to the other report using the button.