There are a number of things to consider if you want a meaningful comparison between runs:
Are you using a chest strap for accurate recording of HR?
Are you running the same route with the same changes in elevation?
Are you running the same time of day and similarly hydrated and fed?
Is the temperature the same for each run?
Is the wind the same for each run?
Is your day to day stress the same?
Each of these will affect HR and some will affect pace. As you can see, comparing the two as you are, isn’t the right way to benchmark progress or lack of it. Try to benchmark once a month or every couple of months, when all of the above are comparable.
For comparison, I’ve attached an image of my average HR and pace for all runs over the last 10 months.
I’m definitely fitter now than I was in January and at a race at the end of August, knocked three minutes off the previous year’s time. My average HR (which matched my AnT) and max HR for the race was exactly the same as last year but I was quicker. However, my day to day pace and HR are not comparable for all the reasons above.