I can confirm that the following sequence of commands worked on both of my 1804 LTS servers that were affected by this issue...
add-apt-repository ppa:phpmyadmin/ppa apt-get clean apt-get update apt-get purge phpmyadmin apt-get install phpmyadmin
I can confirm that the following sequence of commands worked on both of my 1804 LTS servers that were affected by this issue...
add-apt-repository ppa:phpmyadmin/ppa
apt-get clean
apt-get update
apt-get purge phpmyadmin
apt-get install phpmyadmin