I am a hairstylist so I use the app almost hourly when I'm working. If my phone's screen closes to save energy my Square App defaults to offline. I have to turn wifi off then on to get it to be online again. I didn't change anything, I never used to have to do this when I first started using this app. It seems like it changed when you started charging for the second level membership.
Have you tried the basics in troubleshooting? Deleting and reinstalling the app? Making sure it's up to date? Powering your phone off and then back on?
