Yes, I have that as well. I think I saw your posts about it, but I'd forgotten them, so I'll go back and have a read. Thanks.
I have Victron monitoring all over everything and I can see that the Ablemail is maintaining a constant voltage, but it's at just under 12.2V, and I'd prefer it a bit higher. However, it's been like that since I built the van so it's probably not the direct cause.
I've just been on a couple of days away, with a 2-hour trip trip in each direction, and the start-stop kicked in on the way back, so hopefully the battery is now happy. I'll keep an eye on it for a bit.