When you say update to the latest Raspian are you referring to Jessie or Stretch? I’ve been running the same system for many years and it’s running Wheezy right now. I just updated the firmware and I also can’t access the unit on port 8080 and when I default to the standard port 80 I get a page with:
OpenSprinkler Pi (OSPi) Pre-Configured SD Card
Oct 29, 2013
So I’ve probably been running this system for more than 5 years.
I updated because I’ve been working with integration into Home Assistant and the API wasn’t working properly.