Nuendo and Cubase having problem with forks

In Nuendo and Cubase I’m used to have screen problems with dynamic forks, which prolonguie in the score editor when moving back and forth in my scores in the panorama view measure by measure. Without any realizable reason they suddenly prolongue over the whole screen. Moving back some bars, they suddenly stop like editied in correct position. This was acceptable for me, however disturbing. But now I experienced, that these sometimes over dozens of measures expanded fork are exported to an created mxml file and appear also in the created Dorico file. They don’t make any sense, are looking crazy and cause a lot of post editing time. Anybody experienced it too?