Featured post Image too large, does not seem to fit itself inside the div

Hello,

We are using the BlankSlate blank theme for our website and everything is fine except the featured image. We tried for several days to get it fixed using all the solutions provided almost on every google search result page available.

We embedded our website with the latest versions of Bootstrap und JQuery if that helps.

And we didn’t touch anything in the functions.php file at all and it always worked for us on other website with BlankSlate.

Does anyone have any idea what may cause this?

Thank you in advance.

~Deborah

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