I have a similar behaviour on my system. I also was expecting the BMS to keep the CCL very low when the battery is full, but alas, not all BMSs work 100% properly. My battery is a V-TAC one, with unknown BMS (registers as LG on the Venus). I was also seeing it switching constantly between charge/discharge when full, also the charge controllers would constantly ramp-up/ramp-down. What’s worse, that was keeping the cells working, hence raising the battery temperature, even when there was no need whatsoever to keep using it.
So, I put together a node-red flow to limit charge current via DVCC to 5A when the battery hits 100% and revert back to 100A when under 97%. Here’s the relative thread: