Symptoms
#1 Package Deployment Stuck in loop
#2 Only the user who deployed the package is able to see the Workflow when navigating to the 'K2 Application'.
Diagnoses
#1 This is related to the new Sharepoint UI issue: https://help.k2.com/kb001792
Resolution
#1 After switching back to Classic view as per (https://help.k2.com/kb001792), we were able to deploy the package successfully.
#2 This is currently expected behavior. This workflow needs to be Shared to 'Everyone' or the user of your choice via the File > Share option. https://help.k2.com/onlinehelp/k2appit/UserGuide/1.5_Update3/default.htm#Build/Workflows/Save_Your_Workflow.htm?Highlight="Share workflow"