There's no particular reason why. It's not supposed to happen. Your entries are continually saved to the cloud but when something goes wrong, you should see a message popping up to tell you there is some sort of connection problem, etc.
To ensure you don't run into problems using PTO, you should use only a PTO-supported browser and preferably in incognito mode.
Before going back into PTO, you may like to do the following:
- Clear cache and cookies (and I'd also do history);
- Restart browser; and
- Restart computer/device.
If this problem persists, send the return to Support from within PTO and give them a call.
Still an AllStar