Perfomance degradation compared to vanilla with the same config

[vadv]

vanilla:

pgbench -M prepared -S -s 10 -p 6432 -h 127.0.0.1 -P1 -T180 
Scale option ignored, using pgbench_branches table count = 10
starting vacuum...end.
progress: 1.0 s, 12637.7 tps, lat 0.078 ms stddev 0.054
progress: 2.0 s, 12991.0 tps, lat 0.076 ms stddev 0.069
progress: 3.0 s, 12806.6 tps, lat 0.077 ms stddev 0.053

current version:

pgbench -M prepared -S -s 10 -p 6432 -h 127.0.0.1 -P1 -T180 
Scale option ignored, using pgbench_branches table count = 10
starting vacuum...end.
progress: 1.0 s, 8209.9 tps, lat 0.121 ms stddev 0.114
progress: 2.0 s, 8436.1 tps, lat 0.117 ms stddev 0.092

[vadv]

config

[databases]
vadv = host=localhost dbname=vadv
[pgbouncer]
logfile = /home/vadv/.pg/pgbouncer/git/pgbouncer.log
pidfile = /home/vadv/.pg/pgbouncer/git/pgbouncer.pid
listen_addr = 127.0.0.1
listen_port = 6432
auth_type = trust
auth_file = /home/vadv/.pg/pgbouncer/git/users.txt 
pool_mode = transaction 
server_reset_query = DISCARD ALL
max_client_conn = 100
default_pool_size = 20

[kvap]

fixed