Prevent "LIST ACTIVE group" for specific nntp servers?

[Bruno Hertz]

Hi folks

my ISP just moved their news feed, now apparently using Chiparus for
load balancing. As it happens, article numbers now come out wrong when
Gnus issues "LIST ACTIVE group" during updates on that server. I
informed them, but it's not clear yet whether it's a misconfiguration
issue or a bug.

Anyway, I'd like to prevent LIST ACTIVE for groups on that server and
rather have Gnus step into the group (via GROUP apparently) for
gathering article counts, at least until that issue is fixed. So
anybody knows if and how this can be achieved?

Thanks a lot, Bruno.