@Gordonbp I see 2 questions..
1) the lock - another process has it locked aka "there's another installer running" ...
And
2) Installing software still needs to run "dpkg --configure -a" command ...
1 this is by design and not a LL feature; if you have say Updates running and try to install an app, the updates will "lock" until the process is completed.
and vice versa - if you are installing via CLI or another(Synaptic etc) it will lock and updates cannot run.... Synaptic will lock while it open even if not installing....
2 kinda goes hand in hand; you will get this prompt - typically if you have cancelled an update/install mid way.
If you receive this prompt - in terminal run...
sudo dpkg --configure -a
Allow to complete, then rerun updates or installer..