When I edit a forum post, images revert back to a different size

Hi,

I do a lot of forum challenges so I constantly update posts when I make progress in said challenges.
I had not updated anything in April but now that I did, I notice that whenever I edit posts, the images I have in them change their size.

Ex:

• Here is how my post looks now. All my images are 105px X 150px

• When I edit the post, even if I don't change anything in those images, a lot of them change their dimensions and I need to set them back to 105px X 150px every time.

Can that be fixed?