Apple has just released a new official version of watchOS 6.1.3 and corrects some significant errors that have been detected. It looks like this review is due to problems with the tool that warns of unusual heartbeat and other minor errors.
In addition Apple has also introduced a new version of watOS 5.3.5
A previous update of watOS 5.3.5 was released about four months ago, so we assume that at this time they are fixing the problems found. In the case of watOS 6.1.3 it all suggests that the problems found are important and therefore the update is recommended as soon as possible.
Of course on my Apple 4 Series I don't notice any higher battery usage failure than usual, but I have no doubt that it's really an update to resolve this. In any case, this new version is now available for download directly from the Watch app of our iPhone, in the General> software update. Keep in mind that you must have at least 50% cash on your watch and have it connected to the charger during the refresh process