Do you have your own domain assigned to the QNAP?
What’s happening is that it’s superseding the built-in (required) certificate. This prevents your PMS from talking to Plex.tv
Jun 06, 2025 18:38:21.976 [139760216591160] WARN - [HttpClient/HCl#3c] HTTP error requesting PUT https://plex.tv/devices/ea267d0ea16f3d99fc2e3a045858eea9f4621c13?Connection[][uri]=http://89.89.74.29:22352&Connection[][uri]=http://192.168.1.194:32400&Connection[][uri]=http://10.0.5.1:32400&Connection[][uri]=http://10.0.3.1:32400&Connection[][uri]=http://10.0.7.1:32400&Connection[][uri]=http://[2001:861:4040:c8a0:265e:beff:fe3e:711]:32400&httpsEnabled=1&httpsRequired=0&dnsRebindingProtection=0&natLoopbackSupported=1&X-Plex-Token=xxxxxxxxxxxxxxxxxxxx (60, SSL peer certificate or SSH remote key was not OK) (SSL: no alternative certificate subject name matches target host name 'plex.tv')
(60, SSL peer certificate or SSH remote key was not OK) (SSL: no alternative certificate subject name matches target host name ‘plex.tv’)
When you have a domain assigned to your QNAP, it’s important to also give that information to PMS in the Settings - [server] - Network - Show Advanced page.
Given this is a curl error 60 (which means the certificate identification it received does not match what it expected – namely plex.tv, we need to look at what caused it. Possible causes:
A Proxy server, with its own FQDN, which is capturing all inbound traffic to the Plex port and not forwarding correctly.
An expired certificate for your domain.
I looked at your Plex certificate and it’s ok.
Unlikely, but possible – Date/time is out of sync with real time and preventing HTTPS (cert operations) from completing correctly.
To answer your question –
I do not think it’s the port because there is inbound traffic.
I think it’s traffic which is using a FQDN URL to connect to the QNAP which PMS doesn’t know about (most common)
To test this:
Using the computer on your LAN,
Open a browser
Open the QNAP Plex port directly ( http://LAN.IP.of.QNAP:32400/web)
– This avoids use of all certificates except Plex’s for browser<-> server
Depending on the results of this test, we will need to look further.
Do you have a PlexData shared folder ? (upper/lower case is required)
Are you using a certificate you created ? (Self Signed)
Jun 08, 2025 15:04:24.421 [140643080383288] WARN - [HttpClient/HCl#b] HTTP error requesting GET https://plex.tv/api/v2/user?includeSubscriptions=1&includeProviders=1 (60, SSL peer certificate or SSH remote key was not OK) (SSL: no alternative certificate subject name matches target host name 'plex.tv')
Jun 08, 2025 15:04:24.421 [140643065793336] DEBUG - MyPlex: using cached data for request for https://plex.tv/api/v2/user?includeSubscriptions=1&includeProviders=1
Jun 08, 2025 15:04:24.422 [140643080383288] WARN - [HttpClient/HCl#e] HTTP error requesting GET https://plex.tv/api/v2/features?X-Plex-Token=xxxxxxxxxxxxxxxxxxxx (60, SSL peer certificate or SSH remote key was not OK) (SSL: no alternative certificate subject name matches target host name 'plex.tv')
Jun 08, 2025 15:04:24.422 [140643038370616] DEBUG - FeatureManager: Using cached data for features list
Jun 08, 2025 15:04:24.422 [140643065793336] DEBUG - MyPlex: username is guill575, login is guillaume@9business.fr, home is 0, no pin
Jun 08, 2025 15:04:24.423 [140643080383288] WARN - [HttpClient/HCl#f] HTTP error requesting GET https://plex.tv/media/providers?X-Plex-Token=xxxxxxxxxxxxxxxxxxxx (60, SSL peer certificate or SSH remote key was not OK) (SSL: no alternative certificate subject name matches target host name 'plex.tv')
I ask because error 60 also can happen when you create your own certificate.
PMS raises the error because:
It cannot authenticate the certificate
The name in the certificate does not reference or allow plex.tv , which is required
Look here:
* Rebuilt URL to: https://backend.example.com/
* Trying 127.0.0.1...
* Connected to backend.example.com (127.0.0.1) port 443 (#0)
* found 139 certificates in /etc/ssl/ssl.cert/cacert.pem
* found 600 certificates in /etc/ssl/certs
* ALPN, offering http/1.1
* SSL connection using TLS1.2 / ******_RSA_***_***_GCM_*****
* server certificate verification OK
* server certificate status verification SKIPPED
* common name: *.example.com (matched)
* server certificate expiration date OK
* server certificate activation date OK
* certificate public key: RSA
* certificate version: #3
* subject: OU=Domain Control Validated,OU=PositiveSSL Wildcard,CN=*.example.xyz
* start date: Mon, 04 May 2019 00:00:00 GMT
* expire date: Wed, 07 June 2021 23:59:59 GMT
* issuer: C=GB,ST=Greater Manchester,L=Salford,O=Sectigo Limited,CN=Sectigo RSA Domain Validation Secure Server CA
* compression: NULL
* ALPN, server accepted to use http/1.1
This shows:
There is a match
Shows the issuer of the certificate
PMS is complaining for you because there is no match.