Hi Ita!
Could it be that you’re experiencing the same issue described in this thread?
If not, we’ll need more info in order to troubleshoot, including your template markup, CSS/SASS, and maybe a link to the page where this issue is happening. You might also want to try creating a really simple template with just an image and a hover state box shadow and nothing else to see if that works for you (it works perfectly on my end). If that works for you, then you’ll probably want to take your problematic template and simplify it until you find what part seems to be causing the issue.
Cheers! 