Remote access no longer works. Log says "tls: expired certificate"

I've had channels DVR running perfectly on my NAS for months, no problem with remote access. However, as of a couple weeks ago remote access is down! I get an error in iOS channels when I try to connect, it opens Safari then says "Your Channels DVR Server at home can not be reached etc etc".

I've changed nothing in my router or firewall. Port 8089 is forwarded and open. Confirmed open on I can also see my DVR at

The log says "tls: expired certificate".

My Remote DVR settings are: Enable: ON, Port Forwarding: MANUAL. I'm currently running version 2019.11.19.2312 Synology.

I tried turning off Remote Access, then back on again but the certificate was not renewed.

In the end I just deleted the Synology Channels DVR Server then reinstalled it (same exact version). I figured that was the only way to force renew the certificate. Remote access is now working again.

I assume the expired certificate (or the fact that the current version cannot obtain an updated certificate) is a bug?