Unable to connect to server securely with iOs

Server Version#: 1.42.2
Player Version#:16.6.2
<If providing server logs please do NOT turn on verbose logging, only debug logging should be enabled>

Some time ago I quit being able to access Plex remotely with my ipad or iphone. I also can’t access Plex when they are on my home network, although my two Roku players can access it just fine. I have a qnap server, a Comcast router operating in bridge mode, and a Firewalla purple with the server direct connected to the firewall. I hadn’t made any changes when everything stopped working. Since then, I’ve tried numerous setting changes and have got it to work temporarily a couple times, but then it stops again. Not sure how to fix this.

Your ISP is publishing only an IPv4 address.
Your QNAP does not have IPv4 enabled.

The new iOS app doesn’t have IPv6 support yet.

If you enable IPv4 on the QNAP and restart PMS, you should have functionality again.