Assigning Virtual-Addresses to traffic-groups

I have come across an issue where virtual addresses are not staying in the traffic-group that they are assigned to, configuration as follows:

I have address-lists configured, which I am using to specify destination addresses for virtual servers to listen for to split applications (O365) across these vs. I also have multiple traffic-groups, so I can split application traffic across the BIGIP cluster and have them active across different devices. I have assigned the virtual addresses (from the address list) to the relevant traffic-groups, some in tg-1, some in tg-2 and some in tg-3. However, what I am finding is that whenever I modify one of the address lists which are in either tg-2 or tg-3, they revert back to tg-1 which I assume is some sort of default behaviour.

I appreciate the address-lists won't be modified regularly so it shouldn't be much of an issue, although would be good to find out know why this happens.

Does anyone know if there is a way to ensure that these virtual addresses stay in the traffic groups that they are assigned to?