Umbraco 13 timeout setting being ignored?

Questions
1

We’re on v13+ and are experiencing constant time outs. Like 20 seconds will pass and we get a session timeout. I’ve set the timeout as such:

  "Umbraco": {
    "CMS": {
      "Global": {
        "TimeOut": "23:59:00"
      },

But it’s being completely ignored. Is this a bug or incorrectly configured?
Even if a timeout isn’t set the default should be 20 minutes, correct?

This is a companion discussion topic for the original entry at https://our.umbraco.com/forum/113479-umbraco-13-timeout-setting-being-ignored