Are you using Tables with the Sideslope or just a straight sideslope instruction along the length of the corridor? Also are you using a single Template or multiple templates in the corridor.
This could be a Template Transition thing (where one Template says to do one thing and another Template says to do something different so the software tries to morph between the two states - that is the first possibility.
The second possibility is that the sideslope computes at the Computation Interval and at critical points along the road - if at one station it says it is a Cut of 3:1 and the next interval a Fill of 3:1 you will get a transition from one to the other over the computation Interval - this can also be triggered these days by elements prior to the sideslope defined by 2D lines for offset or tables for offset - if you have two nodes very close to each other in the tables, then this will also reflect in the sideslope and if you happen to hit a Cut to Fill transition you could see what you are seeing here.
Failing all of that - I would have to see the model to be able to give you a definitive answer to the question - you can email me at alan_sharp@trimble.com if you don't want to share it publicly and I wiull take a look next week for you.
Try changing your computation Interval, try setting densification to Yes on the Corridor Surface Model, take a good look at the instructions and table / line controls at that specific station, and take a good look at the templates defined around that area -that is where I would most likely start - it is hard to tell from the image exactly what is happening at that spot and if it is occurring over a very short distance or a longer distance
If you do share the model - please draw a circle at the station or send me the station and side of the road where the issue is occurring so that I can find it quickly
Thanks
Alan