Below is the error message when I try to login.
WARNING [http-nio-8080-exec-19] com.sun.jersey.spi.container.servlet.WebComponent.filterFormParameters A servlet request, to the URI https://jira.SERVERNAMEcom/rest/gadget/1.0/login, contains form parameters in the request body but the request body has been consumed by the servlet or a servlet filter accessing the request parameters. Only resource methods using @FormParam will work as expected. Resource methods consuming the request body by other means will not work as expected.
21-Sep-2019 19:39:37.314 WARNING [ContainerBackgroundProcessor[StandardEngine[Catalina]]] org.apache.catalina.valves.StuckThreadDetectionValve.notifyStuckThreadDetected Thread [http-nio-8080-exec-19] (id=) has been active for [124,593] milliseconds (since [9/21/19 7:37 PM]) to serve the same request for [https://jira.SERVERNAMEcom/login.jsp] and may be stuck (configured threshold for this StuckThreadDetectionValve is  seconds). There is/are  thread(s) in total that are monitored by this Valve and may be stuck.
I'm using JIRA version 8.3.3 on a Debian server.
Any insight would be appreciated.
Have you checked the browser console logs?
Open browser's Developer Tools and switch to Console tab, and see the error (red) description. This might give us some clue.
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