What happened to this software? It's a mess!

We recently upgraded to the latest version from an older version (fresh install). What the heck happened to this software?

• The UI is a complete disaster. Looks like a web application from the early 2000s with some random modern elements thrown in here and there. After 4-5 major version revisions, I was not expecting this mess.
• The workflow is unintuitive and confusing. How does a reviewer know that the developer has fixed an issue if the reviewer is supposed to Mark Fixed? The reviewer should "Verify" and the developer should mark "Fixed".
• The phase changes are unintuitive to say the least. I pressed Send to Completed and nothing happens and there's no message to tell me why it didn't change phases.
• I have JIRA disabled. Why is there JIRA button on every review? Just hide it don't disable it.
• A developer completed the review but the reviewer didn't get a "completed" email

Could go on and on. We are software developers, everyone is scratching their heads trying to figure out this tool.