It looks like occasionally a new version of Chrome/Edge deletes the symbolic link and re-creates a regular cache directory. I am not quite sure why they are doing that though, maybe because their cache format changes from version to version.
One way to deal with this would to run the Cache Relocator periodically to check if the redirection is in place.
Otherwise, you can edit the shortcut that you use to open Chrome/Edge and add the
--disk-cache-dir parameter. For example, your shortcut could look like this, where R:\Cache is a RAM disk folder:
"C:\Program Files (x86)\Google\Chrome\Application\chrome.exe" --disk-cache-dir=R:\Cache
This should always use the specified location.