Hi Ren,
I hope you are well today and thank you for your question.
You can try achieving this by using the custom plugin shared in the following topic.
https://colorlibsupport.com/t/portfolio-widget-does-not-show-more-than-10-projects/#post-55822
The above plugin contains following code on line number 47 so just change -1 to number of posts that you want to display in the shapely portfolio widget.
'posts_per_page' => -1,
Best Regards,
Movin