WORKAROUND
There are two possible workarounds to resolve:
For both options, “Healthy” / “Unhealthy” button in the home page is still switching its text by threshold 90. Therefore, it will display “Unhealthy” in green in some cases.
Option 2 is a better option because it will detect an unhealthy condition that is caused by I/O latency as long as that wait type is always significant.
STATUS
Enhancement request number SOSSE-3181 has been submitted to Development for consideration in a future release of Spotlight on SQL Server Enterprise.