We are aware of a bug in Reverse Lookup 2.0.8 where blocked contacts will sometimes continue to ring through. We are investigating the issue and intend to have a fix for it soon.
in the meantime, as a workaround, you can reboot your phone to enable the blocks. You don’t need any special timing, just do it when it is convenient for you and any of the contacts you’ve blocked will go into effect.
Sorry for any inconvenience. We’ll update as soon as we have a fix posted on the Play store.