Taskbar problem

When you uninstall the addons remove their configuration files as well using either Synaptic (complete removal option) or sudo apt purge <addon name> (terminal).
You can also try reinstallation of these packages (if the above suggestion doesn’t fix the problem): gnome-shell-extension-zorin-taskbar and gnome-shell-extension-zorin-panel - I recommend using Synaptic to do that.