Strange warnings on iax2 reload

I am trying to do some testing on Asterisk IAX2 performance, so I started writing some iax.conf files. The problem is that when I try to reload the iax2 configuration in Asterisk, I get a strange warning for every new iax2 friend that I create in the iax.conf file. Please check the warinings below:

This is the test iax.conf. Don’t mind that I am registering all the peers to the same IP address - it’s a performance test setup (simulation of iax2 friends)

[general]
bindport=4569
bindaddr=0.0.0.0
srvlookup=no
bandwidth=high
jitterbuffer=no
forcejitterbuffer=no
minregexpire=600
maxregexpire=600

register => 1000:1000@192.168.99.42
register => 2000:2000@192.168.99.42
register => 3000:3000@192.168.99.42
register => 4000:4000@192.168.99.42
register => 5000:5000@192.168.99.42

[accounts](!)
type=friend
context=test_calls
host=192.168.99.42
disallow=all
allow=alaw
allow=ulaw
qualify=yes
auth=md5

[1000](accounts)
secret=1000

[2000](accounts)
secret=2000

[3000](accounts)
secret=3000

[4000](accounts)
secret=4000

[5000](accounts)
secret=5000

When I try to reload the iax2 configuration in Asterisk, I get some strange warnings. The funny thing is that the warnings are only for the new iax2 friends that are defined in the file. If I reload the iax2 config for the second time, I get not warnings.

TEST_ASTERISK_BOX*CLI> iax2 reload
  == Parsing '/etc/asterisk/iax.conf':   == Found
  == Parsing '/etc/asterisk/users.conf':   == Found
[Jan 19 22:26:47] NOTICE[10687]: chan_iax2.c:12582 set_config: Ignoring bindport on reload
[Jan 19 22:26:47] NOTICE[10687]: chan_iax2.c:12643 set_config: Ignoring bindaddr on reload
[Jan 19 22:26:47] WARNING[10687]: utils.c:1534 __ast_string_field_init: trying to reset empty pool
[Jan 19 22:26:47] WARNING[10687]: utils.c:1534 __ast_string_field_init: trying to reset empty pool
[Jan 19 22:26:47] WARNING[10687]: utils.c:1534 __ast_string_field_init: trying to reset empty pool
[Jan 19 22:26:47] WARNING[10687]: utils.c:1534 __ast_string_field_init: trying to reset empty pool
[Jan 19 22:26:47] WARNING[10687]: utils.c:1534 __ast_string_field_init: trying to reset empty pool
[Jan 19 22:26:51] NOTICE[2488]: chan_iax2.c:11443 __iax2_poke_noanswer: Peer '1000' is now UNREACHABLE! Time: 0
[Jan 19 22:26:51] NOTICE[2497]: chan_iax2.c:11443 __iax2_poke_noanswer: Peer '2000' is now UNREACHABLE! Time: 0
[Jan 19 22:26:51] NOTICE[2498]: chan_iax2.c:11443 __iax2_poke_noanswer: Peer '4000' is now UNREACHABLE! Time: 0
[Jan 19 22:26:51] NOTICE[2492]: chan_iax2.c:11443 __iax2_poke_noanswer: Peer '3000' is now UNREACHABLE! Time: 0
[Jan 19 22:26:51] NOTICE[2490]: chan_iax2.c:11443 __iax2_poke_noanswer: Peer '5000' is now UNREACHABLE! Time: 0
TEST_ASTERISK_BOX*CLI> iax2 show pee
peer   peers
TEST_ASTERISK_BOX*CLI> iax2 show peers
Name/Username    Host                 Mask             Port          Status
1000             192.168.99.42   (S)  255.255.255.255  4569          UNREACHABLE
2000             192.168.99.42   (S)  255.255.255.255  4569          UNREACHABLE
4000             192.168.99.42   (S)  255.255.255.255  4569          UNREACHABLE
3000             192.168.99.42   (S)  255.255.255.255  4569          UNREACHABLE
5000             192.168.99.42   (S)  255.255.255.255  4569          UNREACHABLE
5 iax2 peers [0 online, 5 offline, 0 unmonitored]
TEST_ASTERISK_BOX*CLI> iax2 reload
TEST_ASTERISK_BOX*CLI>

I created the iax.conf file from the sample iax.conf, so I think I am not using any wrong parameters. Does anyone have an idea on what is causing these warnings and if they indicate a problem in the configuration?