Help w/Leak Diagnosis Autotrol Valve @ Resin Tank

[My12by60]

We have a 20-year old system that has an Autotrol 460i valve and a Watertech resin tank. Since I have owned this system it has worked well and required very minimal repair or maintenance. We have city water and have a big blue sediment canister and big blue carbon canister in front of the water softener. A few years ago I replaced the the large, plastic ring between the valve and the resin tank because the ring had cracked. A few months ago, I replaced the flapper kit because I was experiencing leaking from one of the valves.

Now I have a drip coming from the bottom of the large, plastic ring that is under the valve but above the resin tank. I have inspected closely and the leak is not coming from above the ring somewhere higher on the valve.

Should I just try to tighten the ring a bit to see if that stops the leak?

Should I replace the top of tank o-ring due to its age? According to my original paperwork, I need part number 1010429, which I found here: https://www.softenerparts.com/ap43f.htm.

Here is the top tank ring that I replaced: https://www.amazon.com/Autotrol-1035622-Tank-Adapter-Ring/dp/B09FZK4VCN

I don't think that ring could have cracked again and it looked normal when I inspected it.

Any other ideas as to what may be causing a leak coming from this ring?

Thanks for any help.