How could I import a document properly

I have imported and splitted a doxc document, 225 pages (DIN A 4) in Word.

Scrivener splitted it into 1834 pieces. Scrivener behaves very sluggish / slow (since that time) (clicking an item - which may contain only some lines - within the folder the docx is imported to hesitates showing its content for some seconds or so if it is shown at all, often “No response” keeps staying dispayed), shows “No response” very often (in all of the open projects) or all the time and I have to close it with the Task Manager. It shows 15 to 30 % CPU usage for Scrivener. When I click the folder the docx is imported to some text is not shown but available in an item wihtin the folder.

Generally Scrivener behaves very sluggish, very often it shows “No response” what makes its use quite inconvenient.

How could I correct it? How could I import a / that document properly?