any point in walking if HR isnt going up?

My HRM lets me know that when I'm not exerting my heart too much I'm actually burning fat, when my HR is higher then I'm in gaining fitness mode...

That would be a misunderstanding of the various zones. It is actually telling you at that lower intensity that you are burning more fat as a percentage of the total energy your body is burning, but you are burning very few calories. In the "fitness" zone you burn a lot more calories, just a lower percent from fat. Here is the thing you need to realize, even burning less percentage of those calories from fat, you still burn more total calories from fat in the "fitness" zone during the same length of time exercising than you will in the "fat burning" zone. In other words, higher intensity with the higher heart rate will burn more fat total for the same length of workout.

To put that in practical terms, if you spend a half hour walking you will burn much less fat than if you spent that half hour running.

HRMs really aren't made to estimate everything. Consider a Fitbit. Or not 'eating back'.

I've been walking a lot over the past four months. When I started it was a big deal to get over 5,000 steps and now I'm up to the point where going 10,000 steps (about 5 miles) in a day is no big deal. I often make use of my walks to catch up with friends and family on the phone, so I'm not going super fast or getting out of breath on them.

Just a couple of weeks ago I was walking on a treadmill and decided to see how long I could run without stopping. I hadn't run in over a year, when I had trained for a 5k, so I thought it would be a couple of minutes and I'd have to go back to walking. Imagine my surprise when I was able to run for 20 minutes straight!

So walking must be doing something for me.....