[CentOS] cluster ssh edit file with vi slow

Wed Nov 24 08:02:09 UTC 2021
Ralf Prengel <ralf.prengel at rprengel.de>

has anyone a hint:
I have 35 centos systems configured to be managed using clusterssh.
Everythings works fine until I try to edit a file using vi on these 35  
The connections to all targets becomes slow and unusable for minutes  
until the change  in the file is done.
Calling commandos like ls -l is reacts fast.
DNS in the network isn't  fast but working.

Has anyone a hint for me?