Beta app network error

I am getting network error messages using a beta app.

I downloaded TestFlight in January in order to participate in user beta testing and have been using a medical app for the past 6 weeks inputting information every day, recently it has been showing ‘network error ‘ when I try and input stuff, also it won’t let me export a report. I have a good WiFi connection;

I tried to use TestFlight help and support but it just went to a blank apple developer support webpage. According to TestFlight the app has 50 days to run and trying to update the app makes no difference to the version.

Does anyone have any ideas what I should do next?