Hmmm. This is either tangentially-related or an extension of the same issue you experienced… but I started using the terminal within Kate this past week troubleshooting a .bash_aliases function error and noticed that it too was not updating its environment as expected, even after editing the file and running source ~/.bashrc.
I spent 30 minutes only to realize that all of my edits/source reloading were not registering within the Kate terminal for some reason, but were working as expected in Konsole. Once I shutdown Kate and restarted it, the issue was fixed but that seems like a bug and it makes me wary about leaning to heavily on the terminal within Kate (or any other KDE apps outside of Konsole)
One thing that surprises me is the level of “aha” moments using the additional apps. Gwenview and Okular have so many power-user-friendly shortcuts that are intuitive. Lot’s of “Oh that’s nice but it would be perfect if…” moments followed by seeing the option in the settings and/or programmable via a shortcut key