Comment 4 for bug 1888184

We have similar issue but with the same version on both sides.

The checks actually works (it seems), but generates a lot of these errors shown below.

### On a server being checked ###

# Installed packages:
nagios-nrpe-server/focal,focal,now 4.0.0-2ubuntu1 amd64 [installed]

# Output from syslog:
2021-09-30 15:50:22 INFO: SSL Socket Shutdown.
2021-09-30 15:50:22 Could not read request from client *IP*, bailing out...
2021-09-30 15:50:22 Error: (use_ssl == true): Request packet version was invalid!

### On the monitor server ###

# Installed packages:
nagios-nrpe-plugin/focal,now 4.0.0-2ubuntu1 amd64 [installed]
nagios-nrpe-server/focal,now 4.0.0-2ubuntu1 amd64 [installed]

# Output from syslog:
2021-09-30 15:50:22 Remote *IP* does not support version 3/4 packets