My software version is R800XXU1BRH3 which I've received 2 weeks ago.
The one you've mentioned R800OXA1BRH3 is different?
Just had this watch update appear on my phone. Screenshot below
I have been having much better results recently. No software update but once a week I either let my battery run out completely or turn the watch off. Not a forced shut down,but just power down and leave it for half hour or so.
It may be coincidence but I was advised to do it with my phone to allow "self test" and since I have been doing that it's been better. Fingers crossed.
Admittedly it's not amazing but I can't afford to change it, so as long as it works for my runs I'm mostly happy.
Don't buy another. Not that Samsung care.