Yes of course, this is completely normal and expected that a very old version, which released years before the new SSD may not know how it's working (as it provides the status information differently than previous models). I assume the manufacturer tool is a recent version (not one which years old and may not yet support the SSD).
As always recommended: newly installed SSD requires newest possible Hard Disk Sentinel version.
Please install the latest version (or use the automatic update from File menu) to have correct, proper reading.
As you may see in the revision list of the newest version ( https://www.hdsentinel.com/revision.php ):
"reporting correct health for WD BLUE SSDs (previous version may showed 1% health) "
So by the updated version, the Health should be better. The graph on the bottom will show the lower value today (as it shows the daily lowest health measured) but from tomorrow, it will increase back.
Anyway, generally in such situations I always suggest to please use Report menu -> Send test report to developer option. It would confirm the status - but if something is not correct, it is possible to examine the actual situation and assist.