We have configured a Work Folders environment with external access aswell as access on internal IP inside of our organization's network (Split DNS). When accessing Work Folders externally an error occurs: "unspecified error 0x80004005", I then go to control panel and choose Sync now and my files synchronize - this error occurs randomly but doesn't fully prevent us from synchronizing externally. If I click "Sync now" several times it may work approximately 1 out of 5 times.
We are using Reverse Proxy for external access and the Work Folders are configured as a clustered role. Certificate is a public trusted wildcard certificate.