It’s possible it is weak, though a good long charge cycle is needed to bring the battery up. With todays electronics demands on batteries, they only need one bad charge cycle to start a problem. Just not plugging in till late one evening and starting early that next morning can short charge one. One short charge is our suspect, so be sure it’s got one full charge and comes up to 12.8 volts, at the battery, after sitting static for 30 minutes.
The ProGuide AGM has been very good, they either fail or work. Some of the Odyssey brand 31 AGM’s we have seen a slight issue with not staying up on long use cycles We found much of that is short charge cycles, so eliminate that with a fresh full long charge to verify it.
Lithium or AGM they have to be full charged
BCB