CD pipeline, deploy task fails with - ssh: Could not resolve hostname nhaaaaaw..

[gasgithub]

While running CD pipeline in the deploy task I can see that task has issues with decoding ssh keys (why are they decoded?), which sets strange hostname:
Lines 11 and 28 (https://github.com/open-toolchain/commons/blob/master/scripts/deployment_strategies/basic/vsi/utility.sh)

+++ base64 -d
base64: invalid input
+++ chmod 600 bastion.key
+++ ProxyCommand='ssh  -o LogLevel=ERROR -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -i bastion.key -W %h:%p root@NhAAAAAwE

....

base64: invalid input
+++ VsiCommand='-o LogLevel=ERROR -i vsi.key -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null '

....

Creating Build Directory [/home/root/ec2dfb2f-cc48-4121-b42f-b61d3953dea4]
++ ssh -o LogLevel=ERROR -i vsi.key -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -o 'ProxyCommand=ssh -o LogLevel=ERROR -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -i bastion.key -W %h:%p root@NhAAAAA....' [root@172.16.0.4](mailto:root@172.16.0.4) 'mkdir -p /home/root/ec2dfb2f-cc48-4121-b42f-b61d3953dea4'
ssh: Could not resolve hostname nhaaaaaweaaqaaaye....: Name or service not known
kex_exchange_identification: Connection closed by remote host

Same key file that is pasted as bastion-host-ssh-keys and pool-ssh-keys properties, works fine while using ssh from workstation command line and connecting to bastion.