port forwarding - Asterisk/FreePBX behind pfSense – no audio in/out

I have following setup:

ISP modem in bridge mode -> pfSense firewall -> HP2920 switch -> asterisk | VoIP phones

I finally got inbound and outbound calls working but I hear no audio in/out. If I call the phones internally, I hear both sides.

pfSense's NAT port forward is set to any/any for IPv4. I tried port forwarding of UDP ports 10000-20000 but that did not help. From my ISP I heard afterwards that they use ports 16000-32000, tried that, did not work.

These are my port forwarding rules (where I disabled the originals for testing again):

This is my current outbound NAT rule and Manual Outbound NAT selected:

Where PBX is the IP of the asterisk server 192.168.10.10.

These are the firewall rules for the VoIP vlan, the phones are connected to.

You can find the package capture for Wireshark here _{[now expired except for premium (paying) users]}.

Can anybody point me to the right direction, alternative things I could try?

---

Here are the log entries after setting rtp set debug on:

[2017-09-19 16:22:48] VERBOSE[16564][C-00000024] res_rtp_asterisk.c: Got RTP packet from 192.168.30.101:11864 (type 00, seq 000230, ts 5531040, len 000160)
[2017-09-19 16:22:48] VERBOSE[16557][C-00000024] res_rtp_asterisk.c: Sent RTP packet to 192.168.50.1:17234 (type 08, seq 010225, ts 5531040, len 000160)
[2017-09-19 16:22:48] VERBOSE[16564][C-00000024] res_rtp_asterisk.c: Got RTP packet from 192.168.30.101:11864 (type 00, seq 000231, ts 5531200, len 000160)
[2017-09-19 16:22:48] VERBOSE[16557][C-00000024] res_rtp_asterisk.c: Sent RTP packet to 192.168.50.1:17234 (type 08, seq 010226, ts 5531200, len 000160)

Strange thing in the log is the IP 192.168.50.1, which is the gateway of the wireless network?! 192.168.30.101 is the VoIP phone I am calling.

VLAN ID    IP/Subnet          Gateway         Description
10         192.168.10.0/24    192.168.10.1    Servers
20         192.168.20.0/24    192.168.20.1    Computers
30         192.168.30.0/24    192.168.30.1    VOIP
40         192.168.40.0/24    192.168.40.1    Cameras
50         192.168.50.0/24    192.168.50.1    Wireless Staff
60         192.168.60.0/24    192.168.60.1    Wireless Guests

These are the accompanied settings I have on FreePBX:

This is the changed port forwarding setting after KJ4IPS answer (still no luck):