Cannot remove or reinstall Java SDK on Ubuntu 18.04

I’m running Ubuntu 18.04 and cannot remove or reinstall the Java 11 SDK. I originally installed the OpenJDK version and things seemed to be fine but I wanted to install rsyslog today and couldn’t because of some Java 11SDK error.

I have tried running sudo apt remove openjdk-11-jdk and sudo apt purge openjdk-11-jdk

Here is the output from the purge command:

$ sudo apt purge openjdk-11-jdk
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package 'openjdk-11-jdk' is not installed, so not removed
The following packages were automatically installed and are no longer required:
  libice-dev libpthread-stubs0-dev libsm-dev libx11-dev libx11-doc libxau-dev libxcb1-dev libxdmcp-dev libxt-dev
  linux-image-4.15.0-122-generic linux-modules-4.15.0-122-generic x11proto-core-dev x11proto-dev xorg-sgml-doctools
Use 'sudo apt autoremove' to remove them.
0 upgraded, 0 newly installed, 0 to remove and 28 not upgraded.
1 not fully installed or removed.
After this operation, 0 B of additional disk space will be used.
Setting up oracle-java11-installer-local (11.0.9-1~linuxuprising0) ...
Before installing this package,
please download the Oracle JDK 11 .tar.gz file
with the same version as this package (version 11.0.4),
and place it in /var/cache/oracle-jdk11-installer-local,

sudo mkdir -p /var/cache/oracle-jdk11-installer-local
sudo cp jdk-11.0.4_linux-x64_bin.tar.gz /var/cache/oracle-jdk11-installer-local/
sha256sum mismatch jdk-11.0.9_linux-x64_bin.tar.gz
Oracle JDK 11 is NOT installed.
dpkg: error processing package oracle-java11-installer-local (--configure):
 installed oracle-java11-installer-local package post-installation script subprocess returned error exit status 1
Errors were encountered while processing:
E: Sub-process /usr/bin/dpkg returned an error code (1)

It says it’s not installed but you can see it is with this command:

$ java –version
openjdk 2020-11-04
OpenJDK Runtime Environment (build
OpenJDK 64-Bit Server VM (build, mixed mode, sharing)

I also download the jdk-11.0.4_linux-x64_bin.tar.gz and put it into the /var/cache/oracle-jdk11-installer-local as suggested in the output but it makes no difference.

Appreciate any thoughts or suggestions. I just want to get JDK 11 working properly at this point!