Cubic Theme – Resizing Featured Images

Hi There! I recently migrated my WordPress blog (sunshineinseconds.wordpress.com) to BlueHost (sunshineinseconds.com). I was using the Cubic theme earlier, where the featured images for my posts were getting automatically adjusted/ cropped into square blocks on the home page.

However, post migration, I noticed black bars appearing above and below the images, particularly for the photos in landscape orientation.

Is there any way, I can have the same auto-adjustment that was happening on WordPress?

Thanks in advance!