This pop-up means the athlete's internet connection was weak during their last session and the data has not fully uploaded yet.
To fix it, try each of these steps in order. Toggle Airplane Mode on and off. Toggle Wi-Fi off and on. Toggle Mobile Data off and on. Then swipe up to fully close Soma NPT and reopen it.
If the issue continues, delete and reinstall Soma NPT. This clears any cached data that may be blocking the upload.