A good record was ruined by network disconnection 23/8/9

I had a sound sleep last night. When I walked out of my room this morning and clicked 「End sleep session」, an error message pop in, showing that the network is disconnected and the main page needs to be refreshed. Then my whole night record was gone. No any way can have it recovered. My sleep time remians to be 0 hour. It is really annoying to see my record missing only due to the network issue when uploading. IT RUINED MY DAY. So I wonder whether the record could be saved locally in my phone before the upload, or just connected with Apple Health to avoid the data lost risks in such independent measurement only through Pokemon Sleep app.