This issue is occurring on a newly provisioned and updated Raspbian Stretch OS. PiHole is the only package/application/utility that we had installed on it.
Within the PiHole Admin Web Console click Disable then click the 5 minute option. PiHole is then immediately disabled. Click the Enable option and PiHole is then immediately re-enabled.
When clicking Disable within the PiHole Admin Web Console then clicking the 5 minute option there is a small circle on the screen for an extended period of time. PiHole eventually disables after an extended period of time and then the 5 minute count down starts. When clicking Enable to reenable PiHole there is no response from the PiHole Admin Web Console for an extended period of time. Continuing to click on the Enable button re-enables PiHole after a period of time.