gnome-tweak-tool not showing any options for customisation

As you can see that only two options are showing in the gnome tweak tool. All other options are hidden or not showing.

This is happening in Ubuntu 19.10. However, everything is working fine on Linux Mint.

Drag your window to the right to reveal the tab pane on the left. The tab pane contains the different sections. You are now looking to the "General" tab, and that indeed only contains two options.

Maximize your Tweaks window. If you don't see left panel then try to sudo apt purge gnome-tweaks && sudo apt clean && sudo apt update && sudo apt install gnome-tweaks

During removing it shows no dependencies, so it seems, the package itself could contain issues or maybe installed not properly or became corrupted during OS using.