@marceljm thank you very much for your quick support !
Thanks for your quick help, but I have not replaced with previous version.
Instead, I tried to go to Featured Image > Save Image Dimensions, and turn ON the first option – save and use image dimensions (makes posts updates slower). Then I see that new posts start to have their featured images display in the right size again.
I will continue to watch for more new posts, and hope that the problem will go.
Dear Marcel,
Can you guide me how to overwrite the current version by the previous version of the plugin ?
Thank you !