We can't able to change the Category Image from the admin Backend.
Magento ver. 2.3.4
Hello @msgichaudh4312 ,
Try clearing catalog image cache from System > Cache Management->Additional Cache Management->Flush Catalog Images Cache
also, Reindex everything about the category
Make sure you have to write permissions on the media and var directory.
I have removed the image but still showing in the Category page.
If you have setup of Varnish cache, please flush varnish cache as well.
open your website in incognito mode and check if still image is coming.
Have a go at clearing list picture store from System > Cache Management->Additional Cache Management->Flush Catalog Images Cache Esurveyfaqs