How many times has this happened,everybody with a cable tuner has had issues in the past,upgrades of areas and provider info changes unless someone can say 100% in your area you are scanning on the correct provider and qam and a live feed.
The past has had the same problem you have now and will happen again and again and it does not matter what box name you have as they all are having issues and been fixed.
Not in uk so no idea how long a scan takes but 1hr does seem far too long.
If you have a working vm box or enigma2 take all your settings off that and enter it into kv reboot router and box and scan again.
People may have had boxes working for years on same info but things do change and blank screen will happen using old non working info.