Tomcat Manager not opening despite correct tomcat-users.xml

I know this is similar to other questions on stack, but since none of the solutions have worked hopefully I can get help here regardless. I'm using tomcat9, and when setting the tomcat-users.xml, this is my file contents:

<!--
  Licensed to...under the License.
-->
<tomcat-users xmlns="http://tomcat.apache.org/xml"
              xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
              xsi:schemaLocation="http://tomcat.apache.org/xml tomcat-users.xsd"
              version="1.0">
<!--
  NOTE:  By default... web
  application.
-->
<!--
  NOTE:  The sample user ... something appropriate.
-->

  <role rolename="tomcat"/>
  <role rolename="role1"/>
  <role rolename="manager-gui"/>
  <role rolename="manager-script"/>
  <user username="tomcat" password="<must-be-changed>" roles="tomcat"/>
  <user username="both" password="<must-be-changed>" roles="tomcat,role1"/>
  <user username="role1" password="<must-be-changed>" roles="role1"/>
  <user username="admin" password="" roles="tomcat,manager-gui,manager-script"/>
</tomcat-users>

(comments shortened for your viewing pleasure)

For debugging purposes I made the passwords empty, but using text instead doesn't fix the issue. I am making sure to restart tomcat as well. I'm not entering my user account's information into the tomcat-manger prompt -- I've been entering the info for the admin user I created. When attempting to log in, I simply get the login prompt repeating over and over endlessly, until I hit cancel & am greeted with a 401. Any ideas?