Satellite location and data issues

For some reason i have to have my phone unlocked for app to work. I normally go for a run but got the app to keep track of my process. But everytime I lock my phone then turn it back on there’s missing data and position and time… Can anyone help or is the app faulty?

Hi. What device do you use?

I have a OPPO A57 surly that couldn’t be the problem

Please go to app settings and open “Battery optimizations dialog”.
Turn off any optimizations in place where you see (?) signs.