My Anytone 878 (it will be the same on 578) APRS beaconing was working absolutely fine for a long time. Just few days ago I realised my radio is positioned in China. I quickly realised that in my CPS the APRS option fixed location beacon is turned on. It means the radio is not using GPS antenna to send location. Rather than that it send a fixed position which by default is set up to China. Surprisingly the drop down menu where I can change option ON to OFF is grey, it means it is inactive. What is going on? See the picture below.
Later on I have realised that probably it happened when I updated my CPS and also the firmware to the next version.
Bingo! I found the problem. If you go to top menu, click tool and then options you will find all checkboxes are not selected. I had to select GPS (and also APRS). When I went back to APRS tab, I found the fixed location beacon is active again 🙂