Arch Linux - rsync succeeds but prsync does not work

I am moving a large number of files from one PC to another. The two PCs are in 192.168.0.0/24. I started by ryncing all music I had on my source PC to my new PC.

> rsync -P --recursive 192.168.0.201:/home/oldpc/Music /home/newpc/
oldpc@192.168.0.201's password: 
receiving incremental file list
Music/helloworld.mp3
...

The command completed without issues. My

/Documents

folder has over 10000 small files, which would consume a lot of time to transfer one by one. So I found

, which is able to rsync in parallel. I installed

-pssh

from AUR. I took note of this manual and wrote my command.

> prsync -H 192.168.0.201 -l oldpc -p 32 -A -x "-r -P" /home/oldpc/Documents /home/newpc/
Warning: do not enter your password if anyone else has superuser
privileges or access to your account.
Password: 
[1]  16:14:44 [SUCCESS] 192.168.0.201

The command completed in a split second, with no file changes made on either end. I tried the same command a few more times, but it always failed.

> prsync -H 192.168.0.201 -l oldpc -p 32 -A -x "-r -P" /home/oldpc/Documents /home/newpc/
Warning: do not enter your password if anyone else has superuser
privileges or access to your account.
Password: 
[1]  16:15:20 [FAILURE] 192.168.0.201 Exited with error code 255

After waiting a few minutes, I tried one last time, where it succeeded and exited immediately once again without any actual file transfer. What is wrong with my prsync command?