Health-check issue on Kong

I have faced health-check issue multiple time on Kong CE 2.6 version where health-check stops working and i have to restart the Kong to make it work.

sometimes it works for few and not for others in that scenario also i have to restart the kong to work it 100%.
I have almost 200 upstreams created with some having 1000 and some 10000 slots.

i also have enterprise edition but never faced such issue.

anyone has any idea about this, as this is getting worst day by day, and it is very hard to take restart of kong every alternative day.