Please try the following:
Close Dimensions and any associated software (e.g. Asset Manager, Import Utility etc.)
On the Windows Search bar, type 'Display Settings'
On the Display Settings window, scroll down and search for Display resolution
Change the resolution from Recommended to smaller value e.g. from 1920 x 1080 to 1280 x 720
When prompted by Windows, click Keep
Launch Dimensions and check if the issue is resolved.
Change the resolution back to the Recommended value
If the issue persists, please raise a new case online and reference the title of this article.