This problem is occuring across all android/apple/windows devices, and across laptops and phones. Only certain apps and websites can not "connect to server" and get a "error with SSL" message. This error occurs in apps like whatsapp, snapchat and instagram. We are able to access these apps using mobile data. When we connect to other wifi networks on our phones, the apps & websites can load normally. Also websites such as twitter and facebook do not load, and this occurs across all browsers- safari, chrome and internet explorer.
We have had every kind of reset, and even ordered a new router & hub, and still the problem persists. All our settings have been reset - there are no parental controls turned on. The BT engineer was baffled.
Previously we were able to change our DNS server to "manual", and this fixed the problem. However now even this is not working. I think this maybe something to do with our DNS settings or ISP at the router level. Can someone who knows about these things help? Thanks!
This has nothing to do with your ISP. It has everything to do with your OS and apps. SSL connection is secured via a TSL security protocol from your device.
As TSL 1.0 and TSL 1.1 have been found to have security flaws the protocol is no longer supported by the sites/apps you are trying to use. TSL 1.2 is the current option with TSL 1.3 soon to follow.
You should ensure your devices/apps are fully updated to support no lower than TSL 1.2.
TSL - Transport Security Layer.
Edit TSL 1.1 is still being used by many sites/apps but will shortly be phased out. Always ensure your OS and apps are fully kept up to date.