SourceTree bug report V3.4.8 - Unable to add server RSA signature on new installs

[CryosTechnologies]

I was setting up a new dev computer and on other installs I connect source tree to my bitbucket cloud repo using an SSH key. the SSH key manager is Keepass using KeeAgent. This has worked well in the past.

I followed these steps:
1. Download the latest version of source tree (V3.4.8)
2. Installed keepass with keeAgent and opened the existing database file with ssh key - key is successfully loaded.
3. installed and opened SourceTree
4. set repository address to my repo: ssh://git@bitbucket.org/[WorkspaceName]/########.git

At this point, on new installs, Source tree then prompts that it does not know the RSA signature on the server and askes if i want to add it. Normally I click yes and restart the process and everything works fine.

On V3.4.8 however, after adding the address, source tree says that it is an invalid repo address. clicking on details, it looks like it is printing the terminal error message saying (something along the lines of) "unknown RSA signature. Type yes/no to add it to the store"
There is no way to type yes in this details window.
I repeated this in the terminal and although I can type yes there, it responds saying I have insufficient access rights.

I finally resolved this issue by uninstalling V3.4.8, installing V3.4.1 and repeated the above steps. This time source tree shows a prompt message asking if I want to add the RSA signature to the store. As usual, I click yes, restart the process and the repo is then cloned successfully.
Subsequently, I can update to V3.4.8 and it continues to work.