Please tell me where the size of this square for cropping a photo is edited? By default, all groups have a maximum size of 700 pixels.
In the style theme 300x300, but for some reason, by default it cuts to 240x240

no idea?

This is something you would need customisation to achieve. I have moved your ticket to community support to see if anyone here may be able to assist, but there is no way of doing this with the built in software

@Marc StridgenI found this setting in init.php file