1. Open the Settings > Authentication > Session IP address pinning setting.
2. Toggle the setting to "disabled" and click save.
3. Toggle the setting back to "enabled" and click save.

This leaves the setting in the position that you've chosen, but the act of toggling it off and then back on clears a site cache for your site.

After doing this, please let us know if you find that the file delivery issues resolves. We're testing to see if this is the source of login/connection failures that are occurring intermittently with the successful connections.