question

Based on the information provided, my thoughts are that these batteries are not being charged correctly and as such haven't had a proper opportunity to resolve any imbalance. This has also likely accumulated over some time.

The VictronConnect screen images (apart from the very last) show that the battery did not receive a proper charge (sufficient to balance the cells) for over 44 days.

The VRM plot for the ~6 day period shown also supports this, over those multiple charge cycles the absorption voltage was only ever reached once, and that was during the very last charge cycle. In addition it does't look like the absorption voltage was maintained for very long (I can't tell from the time scale, but I assume only 15 min based on the absorption period set).

The Victron Smart Lithium batteries are quite effective at resolving accumulated cell imbalance and then maintaining it, but they need to be given an opportunity to work. As already pointed out, the balancing function is only active above a certain voltage threshold and this needs to be maintained for a sufficient duration.

This is what a full charge cycle (according to Victron specs for their Smart Lithium batteries) should look like in a similar system - note that the absorption voltage (28.4V) is continuously maintained for 2h, with the charge current fully tapering off.

In a system controlled by a Lynx Smart BMS that unit is the brains, it will only trigger an absorption cycle if either of the 2 trigger criteria are satisfied - 'Repeated absorption interval' or 'SoC threshold'. So if you are doing light discharge/recharge cycles on a daily basis it will not recharge to absorption voltage every day and that is not necessary, only when either (or both) of those conditions are satisfied will it increase the CVL from 27.0V to 28.4V.

If you share a screen image of your Lynx Smart BMS charge settings that would also be helpful, but in general I recommend to increase the absorption time to the Victron recommendation of 2h (like already suggested) and give the batteries a proper full charge cycle, then see how it goes for a few cycles after that.

Note that for really badly out of balance cells, sometimes an even longer absorption period (like 8 to 12h) is necessary as a once off measure for the balancer to transfer the required amount of energy throughout the cells, you just need to monitor how well the cell voltages balance up.