Socat error inside Linux Network Namespaces

I'm trying to run socat forward ttyACM0 into UDP. It works with command.

socat UDP-LISTEN:14550,fork,reuseaddr FILE:/dev/ttyACM0,b57600,raw

Problem is, I need to access socat via ip address, which is inside netns. I tried to enter this command:

ip netns exec int socat UDP-LISTEN:14550,fork,reuseaddr FILE:/dev/ttyACM0,b57600,raw

, which displays error:

2024/10/10 14:14:37 socat E read(5, 0x1d54000, 8192): Connection refused
2024/10/10 14:14:38 socat E read(5, 0x1d54000, 8192): Connection refused
2024/10/10 14:14:39 socat E read(5, 0x1d54000, 8192): Connection refused
2024/10/10 14:14:40 socat E read(5, 0x1d54000, 8192): Connection refused
2024/10/10 14:14:41 socat E read(5, 0x1d54000, 8192): Connection refused
2024/10/10 14:14:42 socat E read(5, 0x1d54000, 8192): Connection refused
2024/10/10 14:14:43 socat E read(5, 0x1d54000, 8192): Connection refused
2024/10/10 14:14:44 socat E write(5, 0x1d54000, 44): Connection refused
2024/10/10 14:14:45 socat E read(5, 0x1d54000, 8192): Connection refused
2024/10/10 14:14:46 socat E read(5, 0x1d54000, 8192): Connection refused
2024/10/10 14:14:47 socat E read(5, 0x1d54000, 8192): Connection refused
2024/10/10 14:14:48 socat E write(5, 0x1d54000, 40): Connection refused
2024/10/10 14:14:49 socat E read(5, 0x1d54000, 8192): Connection refused
2024/10/10 14:14:50 socat E read(5, 0x1d54000, 8192): Connection refused

How to properly run socat inside netns?