For example, if you have the IP Redirect set up on a USA store, to redirect AU customers - you would get blocked because you are in AU.
Normally you won't get redirected, but if you do you can work your way around it.
If you just try to go to some-store.myshopify.com/admin, you will get redirected.
The solution is to add /themes/ to the end of the URL.
So if you are trying to log into the store (which you are blocked from) via some-store.myshopify.com/admin, try logging in to somestore.myshopify.com/themes instead, and you won't get redirected.