For some reason, I can’t remove items from cart by doing it from the “Cart Widget”.
I am using the sidebar cart.
Try adding to the cart and removing it from the sidebar widget to reproduce the problem.
Please deactivate all the third-party plugins, activate the parent theme clear cache, and check back.
If the problem continues then leave all the third-party plugins and provide with the admin panel login details of the website with the permission to debug then we will troubleshoot with the theme plugins.