Autopilot Tri-Sensor leaking after o-ring replacement

[EquestrianNancy]

I just replaced my salt cell and replaced the Tri-Sensor O-ring at the same time due to a leak. I did not replace the Tri-Sensor because I have not gotten any bad readings on it. I made sure to use the appropriate lubricant purchased from INYO Pools. Got my system running again and the tri-sensor is still leaking. Any ideas on why it would still leak?

 

[kimkats]

I am not sure so here is a bump to get more eyes on it.

 

[ajw22]

Examine the O ring for imperfections and try another O ring.