Web filtering not picking up user

Is this a Server Protection Client? So there is Intercept X for server installed? Check if this server is in the Best Protection EAP. 

No, no server protection client

Further to that, it's still listed in the Sophos documentation

https://docs.sophos.com/nsg/sophos-firewall/18.5/Help/en-us/webhelp/onlinehelp/AdministratorHelp/Authentication/SophosAuthenticationForThinClient/SATC/index.html

And there's even a step by step document here: https://support.sophos.com/support/s/article/KB-000036877?language=en_US

The authentication part is working fine. It recognises and authenticates the user. It's just that the web policy doesn't recognise that authentication.

SATC was removed due the issues within SATC. It does not work with Internet Explorer, it does not work with Chrome anymore. It will not work, if you have enhanced AV protection by several AVs installed etc. 

https://bugs.chromium.org/p/chromium/issues/detail?id=930750

Therefore SATC was removed and put into EoL state. It got replaced by Server Protection (Intercept X for Server) and a new feature in V19.0 with the legacy proxy. 

Using V18.5 and Intercept X will work like before in SATC.

Using V19.0 and new feature multihost is a new technology to implement a terminal server authentication. You need to have v19.0 for this but you do not need intercept x. https://docs.sophos.com/nsg/sophos-firewall/19.0/Help/en-us/webhelp/onlinehelp/AdministratorHelp/Authentication/HowToArticles/AuthenticationConfigurePerConnectionAuth/index.html#create-firewall-rules-for-multi-user-host-traffic

So, if a customer has a Sophos XG Firewall and doesn't use Sophos Antivirus, they can't have user based web filtering on a terminal server??

They can use the new feature in V19.0. 

Version 19 isn't in general release though, and for a lot of customers means buying new hardware.

I am not sure, how many customers have a XG85/105 and a terminal server and not Intercept X. That is the only customer affected by this. 

It's not just XG85/105, it's XG115-135, XG210, XG550-750 as well (Rev 1/2). We've got clients that spent $10,000 putting in HA failover hardware devices and now a core function of the firewall they were sold doesn't work and they're being told the only way to get back the functionality you paid for is to spend another $10,000 to replace everything. Bizarre.

Anyway, this particular device I'm looking at is a SFV1C4 - they are on the latest version 18.5.2 MR2-Build380 - how can I fix this issue?

Just XG85/105 are limited to V17.5. All other products will be able to upgrade to V19.0 once its available. 

You are not paying this much for a authentication service, instead for one of the best protection layer products on the market (Intercept X). But thats by the way. 

V19.0 is a EAP Product, so you can install the EAP or you can wait for the GA release in a couple of weeks. 

People buy firewalls for all types of different reasons. For many of our clients, web filtering is a critical component. They want to be able to stop staff using social media but still allow their marketing teams to use it. Being able to control what websites staff can access is a pretty core component of modern day firewalls.

RE hardware, I'm confused by your comments. Are you saying that these models ARE NOT supported by v18.5 but they ARE supported by v19?

People buy firewalls for all types of different reasons. For many of our clients, web filtering is a critical component. They want to be able to stop staff using social media but still allow their marketing teams to use it. Being able to control what websites staff can access is a pretty core component of modern day firewalls.

RE hardware, I'm confused by your comments. Are you saying that these models ARE NOT supported by v18.5 but they ARE supported by v19?

That is not accurate. See The blog post of this screenshot: 

https://partnernews.sophos.com/en-us/2020/02/products/xg-firewall-v18-which-hardware-models-are-supported/

UPDATE: Information in this blog post is no longer up to date. Please see the latest information here:
https://partnernews.sophos.com/en-us/2021/02/products/updated-xg-firewall-v18-which-hardware-models-are-supported/

Thanks. This is great to know. Probably worth removing the incorrect information from the website?