Via is set to automatically be logged in after you first login. The token expires every quarter so you'll need to login again if the study spans a longer period than a quarter.
However, in some instances it can log out. To ensure all data is synced, please look at the top left corner of your browser and look for the V icon similar to below image:
If the V icon is grey, click on it and login with your username and password. Then select the V icon again and select Test Connection option so any offline data will be synced. The count of items listed under Test Connection option will go to 0 once the data is synced.
If the V icon is pink already, simply select the V icon and select Test Connection option so any offline data will be synced. The count of items listed under Test Connection option will go to 0 once the data is synced.
I can't find the V icon at the top right corner?
If you cannot find the V icon in the top right corner, it may be collapsed with other extensions running on your browser.
For Chrome, select the puzzle icon at the top right to see all active extensions. Select the pin next to Via so that the extension will be visible in the top right corner of the browser.
For Edge, select the 3 horizontal dots on the top right and you should see the V icon in the top tray as below: