I have some good news.

I raised an issue with my ISP. They've issued me with a new IP. I don't know what else they did but it has resolved the issue.

I have also raised an issue with redhat developers working on openssh.

They said this is a known issue especially in the VMWare community:

https://communities.vmware.com/thread/590825

The issue is related to a change in OpenSSH_7.8 relating to the QoS flag.

The workaround is to use the following in your ~/.ssh/config file

Host *
    IPQoS=throughput

I will not mark this as the answer until I can confirm it working on my end.

I have some good news.

I raised an issue with my ISP. They've issued me with a new IP. I don't know what else they did but it has resolved the issue.

I have also raised an issue with redhat developers working on openssh.

They said this is a known issue especially in the VMWare community:

https://communities.vmware.com/thread/590825

The issue is related to a change in OpenSSH_7.8 relating to the QoS flag.

http://www.openssh.com/txt/release-7.8

The workaround is to use the following in your ~/.ssh/config file

Host *
    IPQoS=throughput

I will not mark this as the answer until I can confirm it working on my end.