If you have ATT as your home ISP, turn this setting off so they stop filtering your traffic and blocking the app.
Login to your ATT Fiber account at https://cprodx.att.com/cmp/cmpportal/
Select "DNS Error Assist" at the bottom left ->
After the next screen loads, turn "Allow use" to OFF ->
Changes can take up to 24-hours, but ATT will now stop filtering your traffic and blocking the App/TV Guide from downloading.