Have a new issue where most people with iPhone's cannot load a Anywhere URL. It works on all desktops and Android devices however most times when on iPhone it will not load.

VTScada was upgraded to latest version, same issue. Can't seem to find any discussions of others reporting this. Just looking to see if anywhere here has seen this.

The server logs this Windows Event when it happens.

ID 1001
VTScada
Server TLS error 0x80090327 detected (1) for IP XXX.XXX.XXX.XXX

Hey, the VTScada dev folks have noted the following:

"
The error code maps to "SEC_E_CERT_UNKNOWN" which can mean a few things: the certificate is bad, the certificate is unsupported for some reason (e.g. it failed Safari's checks), or the certificate is unknown. Where is the customer's certificate from (e.g. a public CA certificate, internally issued certificate), and has it just been renewed?
"

Can you let us know what version of VTScada you are running? One dev is curious if you are using TLS 1.3 but using a version of VTScada from before that was supported. Also any info you can provide to help with the thoughts above would also be helpful.

We were on 12.1.09, TLS 1.3 was not supported. We upgraded to 12.1.36 which did enable TLS 1.3 support, same issue.

The cert if from a public source (Godaddy). A SSLLab's test shows the cert as good, https://www.ssllabs.com/. It was upgraded about 1 month ago, I am not sure if it worked prior to this certificate upgrade or not, will ask. It works 100% of the time on Windows Desktops and all Android phones, its only iOS where this happens.

We tested with around 10 iPhones total. I dont have the iOS versions or Safari versions of each but might need to retest and get them for deeper troubleshooting.
4 of them seems to load fine on cell data and Wi-Fi data.
4 of them wont load at all, just a white page.
2 of them load only when on cell data, not on Wi-Fi. The Wi-Fi is nothing crazy either, either basic home internet or business unfiltered internet. Something in the connection changes when using Wi-Fi.

If I use a browser testing tool to emulate certain devices, https://blisk.io/ and https://www.browserstack.com/, it also works 100% of the time.

There are no fancy firewalls Infront so i know its nothing being blocked there.

This VTScada is running in Azure. Windows server 2022