Hello,
from my perspective (based on my comment) your required actions are
Decision
As a prerequisite to follow-up procedures - decide whether you want to use
[1] Latest LibreOffice packages from TDF (Download LibreOffice | LibreOffice - Free Office Suite - Based on OpenOffice - Compatible with Microsoft)
[2] Latest LibreOffice packages from Ubuntu, delivered by Ubuntu maintainers (Ubuntu Launchpad LibreOffice PPA) (as of today this PPA delivers version 7.1.1.2 and most people would recommend this way to go)
Clean Up
To create a clean base for subsequent installation, cleanup up your mixed installation using the following procedure:
dpkg --list | awk '/ii/&&/libreoffice/||/libobasis/{print $2}' | sudo xargs apt purge -yes
sudo apt autoremove --yes
(Re-) Installation
With respect to your decision above, select one (and only one) of the following procedures:
Decision [1]:
Repeat step:
Decision [2]:
Perform:
sudo add-apt-repository ppa:libreoffice/ppa --yes
sudo apt update --yes
sudo apt install libreoffice libreoffice-help-en-us
Hope that helps.