LTC2983 Error reporting question, 4 wire connection, PT1000, Kelvin Rsense, Rsense sharing

Hello,

We are using LTC2983 to measure the temperature on four PT1000 probes connected by 4 wires to LTC, Rsense connection is Kelvin type (5 kOhm). Below you can find scheme:

Measurements work properly, but we noticed that disconnecting specific cable from the probe does not generate a measurement error in the LTC (Read Results, bit D24 is always 1).
Disconnecting the following two cables from the probe causes the LTC to report a measurement error:


but...
We have the problem with disconencting the cables below (only when disconencting one per test, diconnecting two at the same time will produce an error), we don't see the LTC reporting a measurement error, but the temperature reading goes up by about 200 degrees Celsius.


We wonder if we are doing something wrong, or is the LTC simply behaving like this when disconnecting a single wire from the two that I have described?
We just want to make sure if we can still improve something in our electronics or in the program, or simply assume that LTC works like that.

Thank you
Best regards
Zbigniew Czerski