Nothing that I can see 
Should I try to set Limits here?
This morning, I did a full “power on cycle” of the MPPTs, the Cerbo and the BMS.
Then I checked via MQTT again and found 2 sets of
BatteryOperationalLimits
1) vebus 261 ( Venus GX VE.Bus port (ttyO5))
2) vebus 276 ( Cerbo GX VE.Bus port (ttyS4))
and
MaxChargeVoltage has different settings 
Which one is used to control the MPPTs?
What is the Lynx Shunt doing exactly, and why are its values completely different to the batteries BMS?
Is the communication to the BMS solid? In DVCC you have set controlling BMS to auto, so if the BMS coms are not solid then maybe Victron falls back to the Shunt as the BMS, and since its values are totally different, DVCC then also reacts different.
I assume thats just a typo, otherwise it would be interesting to know how you combined two GX devices into one system.
You can look up VE.Bus IDs in the VRM device list for example, to find out which devices are ID 261 and 276
The Lynx shunt is NOT monitoring the SolarBattery!
It is used to keep track the DC Distribution in the house 
Those names came from the:
CCGX-Modbus-TCP-register-list
These ID’s are NOT displayed in the device-list of VRM.
I believe this is, because they are part of the Gateway (CerboGX)
…and do not show as individual VRM instances
Last year, I replaced the Venus with a CerboGX MK2
The ID 261 is just a left over on MQTT Broker, from the previous installed Venus
so disregard this ID
Ok, but then the follow up question would be why the Shunt measures such a big voltage difference compared to the battery? I assume the shunt is measuring essentially busbar voltage, while the BMS of course measures voltage on the cells. So you are loosing 1.28V inbetween the busbars and the cells, which is a lot.
Whats the output voltage on the MPPTs at this power level?
I will disconnect the Lynx shunt, to see if it makes a difference - thx for the idea
Correct
I disconnected the Lynx shunt for now.
Comparing the fully charged Battery
BMS voltage = 56.18 @ 1.5A
MPPTs @~55A both ~56.4 Volts
I would think that that is OK?
I will check with a meter to verify the Voltage readings.
I already checked ALL DC connections - and found nothing wrong
not sure where you are getting the other entry from for vebus, should only be one under the cerbo serial number.
As I mentioned above:
I think found something interesting
This is plotting the BMS CCL and the MppOperatingMode.
About 2seconds after the CCL drops to “0” the MPP Operating Mode changes to “0” = Off
after the CCL changes to anything above 0 the MPPOperating mode also changes to 1 and the 2 again
When PV excess feed-in is enabled?
Should that be like that?
here is another zoomed in plot
This is what I was asking about earlier on.
Settling ccl to 0 can have some undesired consequences.
Good morning.
So what must I do to change this?
…and should the ESS thingy not continue, keeping the MPPT running, when DC excess feed-in is enabled??
The system was working the last 7 years, with this BMS.
I suspect some VenusOS or ESS changes, causing this behaviour 
I would log a ticket with BYD, ask them to check the battery and see if there are any firmware updates.
You can also try reduce the battery charge current in DVCC, see if that helps.