tweak bash autocompletion

I am busy with a task from the terminal which is that laborious that it would be of value to tweak something with bash autocomplete. So a standard Debian package is [xournal](https://packages.debian.org/de/buster/xournal) which I don't have installed (anymore) What I *do* have installed is [xournal++](https://github.com/xournalpp/xournalpp) which is launched with 'xournalpp' The terminal does not realise that and tab does not complete all the way. Does anyone know how to fix this?