If saving drawings with a lot of content (containing thousands of vectors and/or big pixel graphics) it may take a few seconds or even up to a minute or more.
It would be nice if not the whole CorelDraw software is locked during this time (process not responding).
Suggestion: As the saving process seems to use only one core of the CPU, wouldn't it be possible to lock only the document which is currently saved and another file could still be edited during this time?
CorelDRAW does support multithreading to move such operations to the background so that you can continue working while the file is being saved, exported, printed,...
You may need to "enable background tasks" in the Options dialog > Global settings to take advantage of that functionality.