It looks like occasionally the new versions of Chrome/Edge delete the symbolic link and re-create a regular cache directory. It is unclear why they do that; maybe because their cache format changes from version to version.
One way to deal with this would be to run the Cache Relocator periodically, to check if the redirection is in place.
Alternatively, you can edit the shortcut that you use for opening Chrome/Edge and add the
--disk-cache-dir parameter. For example, your shortcut can look like this:
"C:\Program Files (x86)\Google\Chrome\Application\chrome.exe" --disk-cache-dir=R:\Cache
where R:\Cache is the browser cache folder on the RAM disk.
This should always use the specified location.