Have you tried clearing cache, using another browser? Incognito mode? Also is it the same using the plugin as well as the HCX manager page?
I would open a support case, they will likely remove and reinstall the plugin.
Or update to HCX 4.4.1 which will install the new one.
If Only HCX Plugin via VC shows duplicate entries ..It is an issue on vSphere Client.
Try clearing HTML Client cache.
Take a snapshot of VC and try the below.
STEPS TO CLEAR HTML CACHE :
service-control --stop vsphere-ui
Clear the user cache:
Clean tomcat cache:
Clean client plugin cache:
Remove/clear the contents of the cmCatalog directory:
(you can use rm -r * when in the directory)
service-control --start vsphere-ui