The second part is correct about an invisible wall. We have two issues being investigated by our QA and Developers after the latest patch. Seems you are running into both issues at the same time! >,<
-
First one about graphics can be found Here.
-
Second one about ramps not working correctly maybe related to the invisible wall you are talking about Here.
These issues are still new and data is being collected. At this time I would believe both of theses to be known issues with the latest patch. I would recommend to follow up in both threads linked about and provide them any data you can so we can get this fixed!
Thank you!