All sessions to postgresql backends are terminated with the SD code

Help!
1

Hello. I have the simple configuration with 2 postgresql servers in backend.
HAProxy version 2.4.12-1ppa1~focal 2022/01/11

defaults
        timeout connect 5000
        timeout client  50000
        timeout server  50000

listen pg_read2
    bind 10.1.107.182:55432
    mode tcp
    option tcplog
    balance leastconn
    option pgsql-check user check_user
    default-server inter 3s fall 3 rise 3 on-marked-down shutdown-sessions
    server pg_bigd3 10.1.107.170:5432 check
    server pg_bigd4 10.1.107.171:5432 check

There are the php application to connect through HAProxy to PostgreSQL. When i do request and close connection in php, HAProxy logs the SD termination state on every request:

pg_read2 pg_read2/pg_bigd4 1/0/35 2113 SD 12/5/4/1/0 0/0
pg_read2 pg_read2/pg_bigd4 1/0/61 6872 SD 14/6/5/2/0 0/0
pg_read2 pg_read2/pg_bigd3 1/0/68 6839 SD 17/7/6/3/0 0/0
pg_read2 pg_read2/pg_bigd3 1/0/78 36249 SD 16/6/5/2/0 0/0
pg_read2 pg_read2/pg_bigd3 1/0/73 6911 SD 17/6/5/2/0 0/0
pg_read2 pg_read2/pg_bigd4 1/0/64 6872 SD 19/7/6/3/0 0/0
pg_read2 pg_read2/pg_bigd4 1/0/71 6886 SD 18/6/5/2/0 0/0
pg_read2 pg_read2/pg_bigd4 1/0/74 36557 SD 19/7/6/2/0 0/0
pg_read2 pg_read2/pg_bigd3 1/0/68 6886 SD 18/6/5/3/0 0/0
pg_read2 pg_read2/pg_bigd3 1/0/71 6901 SD 17/5/4/2/0 0/0

BUT all required data are received (data size is correct and time of request execution is correct) and all works. No any errors is logged.
What it can be?