912is volts/amps

Howdy folks,

Sling 2 LSA, Rotax 912is 1700 hours.

Normal startup my amps would be -2 to -4 until increasing RPM's to 2500 to kick the alternator on. Amps would go positive 1-3 and amps would rise to 13.2-13,5.  Normal flight would be 0 to +1a and 13.2-13,5 volts ALL the time.

Now upon startup, amps start at -3 to -6, increasing RPM to 2500 gets me to -1 to -2 a and volts stay between 12.2 and 12.5 moving up and down so there is alternator power. Big difference.

During flight I maintain 12.0-12.5volts, occasionally it will go to 11.8-11.9 but rise back above quickly. Amps stay at -1 to -3.

If I pop my ECU backup on, basically bypassing the alternator(?), my amps go to +7 and the volts go back to the happy 13.1-13.2.  I am pretty sure I cannot keep the ECU backup on all the time, that seems like a bad decision

I have replaced the battery and switched out all 3 relays in the ECU and still have the issue.

My BELEIF is that Alternator A is struggling to push out enough amps to keep me 13+ volts but is working, keeping me above 12.0.

My HOPE is someone knows something I am missing and can troubleshoot an easier fix than what I fear is wrong.

My FEAR is my alternator has hit its old age and needs to be retired.

Would love any assistance you fine folks have to offer!