Steps to replicate the issue:
What happens?: you will be forwarded to https://www.mohrsiebeck.com/en (general landing page of Mohr Siebeck) without proxy access to the content
What should have happened instead?: free access via TWL Proxy
Again, thanks for creating this ticket and for looking into this. I have checked again, and I can confirm that access now works again as expected for me. I'd like to watch it for a while, but maybe we could close the task for the time being?
We inadvertently removed the proxy config for recently added partners, so others were affected too. This now looks to be resolved!
I'm afraid the relaunch of Mohr Siebeck's website has lead to a major problem. Clicking on the button to read a resource as PDF, you are now redirected to viewer.content-select.com. That is to say, you are forced to access Mohr Siebeck's own viewer over a domain that we cannot access over our proxy. This seems to be hard coded on the publisher's side. Hence, the user's own IP address gets checked which, of course, is not eligible for access to the site.
It seems the problem came about around last week, and it still persists.
We discussed the issue over the weekend on German Wikipedia https://de.wikipedia.org/wiki/Wikipedia_Diskussion:F%C3%B6rderung/The_Wikipedia_Library#Mohr_Siebeck
I would be grateful if you please could take a look at the proxy configuration.
Many thanks in advance!