Sure - there is an excellent summary here: Health Check Mechanisms Against Link Failure
The idea here is to make the health check classify a link as “down” sooner.
It seems that with your current Health Check settings (defaults?) the router considers the link to still be operational, yet the link is too slow to be useful for your purposes. With these settings you are in full control over what link is considered to be down vs.
up.
For example, you can classify the link to be down if ping to google.com takes over 2,000ms 5 times in a row.
Hope this helps!