I confirmed that this is an issue only when ip_hash is used - without it healthcheck fail causes upstream to stop routing requests to failing node. Could use a bit of help understanding:
- is this by design (i.e ip_hash support never implemented) or a bug?

I am happy to create an enhancement/fix but, as a c-newbie, would appreciate a bit of guidance on where specifically to look in nginx or https://github.com/liseen/healthcheck_nginx_upstreams/blob/master/ngx_http_healthcheck_module.c

thanks!