If you can have your computer automatically set the time through an NTP server, that will probably fix it. Just do a search for your operating system about how to get the system time set automatically. If it is already set automatically, it's possible that the Bookdown server clock is not set right.
What's happening is that secure communication between two computers, for reasons I can't remember, check to make sure they agree about what time it is. If they don't, they assume something is wrong and break off communication.