client: Connection error: read tcp 192.168.124.4:44058->106.9.xxx.xxx:8000: read: connection reset by peer

I have two machines, both running Ubuntu 20.04 LTS. Machine A have a PPPoE assigned dynamic public IP address 106.9.xxx.xxx, machine B resides on an intranet with the IP address 192.168.124.4. I installed the latest git master version of chisel on both machines and then do the following test:

On machine A:

$ chisel server -p 8000 --reverse
2021/10/31 14:34:37 server: Reverse tunnelling enabled
2021/10/31 14:34:37 server: Fingerprint ZlIz4ytGpRXNjd7OdOkkbJ/k13Zh2D4lZ534BhVZK2E=
2021/10/31 14:34:37 server: Listening on http://0.0.0.0:8000

On machine B:

$ chisel client 106.9.177.233:8000 R:socks
2021/10/31 14:36:38 client: Connecting to ws://106.9.xxx.xxx:8000
2021/10/31 14:36:38 client: Connection error: read tcp 192.168.124.4:44058->106.9.xxx.xxx:8000: read: connection reset by peer
[...]
^C2021/10/31 14:36:40 client: Cancelled

Any hints for this problem?

Regards,
HZ

Start by reproducing the reported chisel server -p 8000 --reverse and chisel client 106.9.177.233:8000 R:socks commands on Ubuntu 20.04. No source file or test is named; done means identifying why the connection is reset and recording a verified resolution or actionable diagnosis.