Issue with sdbm hash-type (no replies)

We are seeing an issue where using SDBM hash-type that the last server in the pool is getting 100% of the traffic and the first server in the pool gets 0. We also tried adding a 3rd server and the last server still got all the traffic.
All weights were 1.

A config sample:

backend VIP
http-reuse always
option httpchk GET /server-status HTTP/1.1\r\nHost:\ haproxy
balance source
hash-type consistent sdbm
default-server inter 2000ms fastinter 250ms downinter 1000ms fall 1 rise 2 slowstart 10s
server SERVER1 10.0.0.115:8080 check namespace haproxy
server SERVER2 10.0.0.116:8080 check namespace haproxy
server SERVER1:backup 10.0.0.115:8080 backup namespace haproxy
server SERVER2:backup 10.0.0.116:8080 backup namespace haproxy

We were able to resolve the issue by using sdbm avalanche.

Is this a known issue or a potential regression?

Thanks so much for the help!