Ahh, I don't know why.. but I am going to reboot my 7 S9's. I did that before, and then the pool found a block.. I Know... its useless step, but I have a hunch...
Some have been up for 29 days.
I will sacrifice my .00001% of shares for this... then you will see a block will be busted!
I rebooted mine earlier today for the same reason!
Might help, There might be some bad firmware issue that no one has found, and long uptimes cause.
I was more worried about Kano actually working out the math on the downtime of 5 minutes of 7 S9's and the share value not being .00001% :-) I just threw a number out... No need to calculate it - I know you love math... :-) haha