Is there really a reason to write about the problems of CorelDRAW 2019 since no one can answer? The most common incident is that Coreldraw disappears from my screen when, having selected an object, I open the fill docker. The solution for now is one: Ctrl+S all the time and opening again and again the application and the files. Hurdless...
You should first figure out if this is the file or the application, causing it. If it happens with all your files, then you may start CorelDRAW with F8 key pressed and reset it that way. Good luck!
if you starting CorelDRAW with F8 key, and you have a "custom workspace", export it first, because if not it will get lost with the restart.
Thank you Christian and Mike. I'm afraid it's the application, it happens will any file. I also used to reset Coreldraw in previous versions but can not be said that is a good solution.