It turns out that the issue is not limited to Echos. All devices that are on profiles with calendars will not have internet access once their time is back. For example, I have a laptop on a profile that stops access at 10pm and restores it at 6am. At 8:30am, the laptop still does not have any internet access. It is listed as connected to the router in Status, but nothing shows up in the Access logs, blocked or otherwise, after the internet should have come back on for it. I DO see blocked requests during the calendar outage period with the blocked reason “Calendar”.

It looks like once the calendar time starts for a profile, the router instead stops honoring any requests from devices on that profile.