Help with Cubic letterboxing problem

This is a continuation of other threads.

Hello, last time I made this inquiry in another thread.

Hello.
I have just started my blog using Cubic, but there has been a problem.
The only centered photo does not have the black lines at the top and bottom of the photo like the other two photos next to it.
I would like to make them the same, which means I would like to have the black lines on all the photos.
Would you kindly tell me how to do it if you know the way.
Thank you.

This is the site.
https://mazijapan.com/

and the answers were like these.

However I would say that you would probably need to change the dimensions of the middle picture to be the same as those to the left and right in order to get the black bars.

You’re getting the letterboxing effect because those images are much wider than they are high. If you need further help, please start a new thread. Thanks.

And I have tried these.
Actually, the photos next to the middle one are 6000 × 4000 and 815 × 543, so I tried to make the middle one the same ratio (2637 × 1760).
But it did not work.
Would you kindly help me here. Thank you.

https://mazijapan.com/

Hi @makisei, if you look at the Cubic theme Showcase page and scroll down to the Quick Specs section at the bottom, the featured image size is 2000 x 1500, which is a ratio of 1.33 to 1 (width to height). The images you are using are 1.5 to 1. Can you try a 1.33 to 1 ratio on the images where the black is showing above and below the image on your main page and see if that takes care of it?

Thank you for kindly helping me!
I tried 1.33 to 1 ratio but still did not solve the problem….
I know this is not a big deal, but it bothers me…
Anyway I will make a new thread and will put URL here too, so I would appreciate it if you still help me.
Thank you.

Now we are here…
I would greatly appreciate if somebody helps me with this problem…
Sorry to bother you with these long sentences and Thank you.