So I've been walking a lot. I've been using Samsung Health (free) and Google Fit (free) to track my walking /running/ hiking. But they both have limitations. Google fit works great about 75% of the time, but sometimes it'll stop tracking and just cut across my route which severely underestimates how far I walked. Samsung health just has a generic "you went this far today" but doesn't track activities as far as I can see, so it's only really useful for my early morning walks. I don't count walking through costco or wal-mart as exercise for my tracking purposes.

What I really want is something that accurately tracks and logs my walks, because my phone apps have been doing a crappy job. HR tracking would be nice, but I really don't need it.

Have you used anything that seems to work flawlessly?

I have a Fitbit Inspire HR that does well for tracking.

You can cycle through maybe 3 button presses to start it recording for each exercise session or it picks up that you’re exercising after a few minutes.

For walks and runs I now use Polar Beat along with a Polar OH1 arm band heart monitor. The App is pretty detailed with pace and heart beat along every step of your route. You do have to pick the activity and start and stop it, but then it keeps it in a log and uploads it to their website. MapmyRun would be my second choice, but I think I had to pay for a subscription versus Polar for free after you buy their HB monitor. I think I've only had mapping problems twice when for some unknown reason my phone could not get good satellite reception.  

I've been happy with my Garmin device.

Considering going with the new gshock.  Can't say if it's any good though.

I have had great luck with the Runkeeper app. Like you I don't care about incidental "exercise", just actual workouts. I found wearables to be a bit finicky.

If you are looking for GPS be wary of devices that use your phone's GPS instead of their own since your phone isn't working apparently.  If you just want step counts avoid wrist-worn counters if you want anything remotely accurate.

Same here, have been using runkeeper for runs, walks and ruck marches for several years.  It's been very consistent on distances (I do about 50/50 known distance courses and repeat trails).  Only real downside is having to carry your phone with.  

Upside is that I use my phone for music via BT while on the move anyhow, and I REALLY like runkeepers verbal status and prompts that also play over my BT headphones since it's coming from my cell (tells me time/distance/pace/etc verbally either every-so-many-minutes or every-so-many-miles)

I've been looking at the FitBit Charge 4 which has it's own GPS but apparently the battery life is horrendous when GPS is on. Like... 3-4 hours battery life from a full charge.
It's also hard to justify $140 for a toy.

Fitbit Charge 3 here. Love it, will not replace until it breaks.