Something else is likely wrong. I even have a 1A unit servicing a dual battery setup in my 96 Dodge Ram
CTD. I wasn’t sure how it would work out but it’s doing fine.
I also have had one on my 98 S-10 literally plugged in for a year.
Some chargers will go to sleep when “full”, then never wake back up. I’ve seen that with Chinese ones, even nicer ones with displays that show voltage. NOCO does “sleep”, I think to satisfy environmental regulations. But it wakes up, checks out, and then tops off the battery.
Maybe the firmware in your CA model isn’t right? I know your outcome isn’t consistent with the three that I own.