Can access via IE/Win10 but not on iPad or iPhone

I have a Pi running the latest version of Volumio (updated yesterday - August 13th). I usually use an iPhone or iPad to control it via 192.168.1.xxx, but don’t understand why the previous way is not working. Any ideas?

Just out of curiosity, would you mind trying “http://volumio”?

Yes, that appears to work! Can you explain why?