Whalebird is listed in the Software application as a snap pack but when I installed it I was logged out and the system would not longer recognise my login password.
Thank heaven for live-USB so I could get back on-line and start looking for solutions.
I tried to use the GRUB recovery mode root shell to reset my password with 'passwd username' as per internet advice but though it was reporting successful update, the system was still not accepting my account password. Things were looking dire.
I eventually was able to see the whalebird package with 'snap list' and uninstall the package with a 'snap remove whalebird' command from the same GRUB recovery mode root shell.
Problem was solved and my account password starting working again though my desktop theme had been reset so I configure it again but the customisations still seemed to be there.
Posted to flag the Whalebird 6.2.5 snap package was a nasty problem (for me) and the solution for anyone in the same boat.