i agree totally with balck-zion. i used value ram 1 time in an old ddr2 667mhz dell but it was all you could get when i refurbed it. ddr2 was is obsolete ..
I used this function on old AM3 mainboards.
But i got in contact with ASUS and they told me (6.6.2017) that there is currently no asus board that supports ecc.
it must at some point since 6.22.2017 bios . since there boards have all the settings for it. .. hard to say when talking to sand language person.
firefox is well known to crash thats pretty normal. especially if playing a video. but all i can tell you is what i kinow and asus hero boards scrub the errors . i dont know if the bios that is out is helping or not. but there are people running 3200 dual rank ram but in the end rank 1 seems to win in performance. they run dual rank no problems. not sure what motherboard shouldnt matter unless its a cheap one.
if you need rank 2 i would get better ram. but if you dont just buy the G.skill flare-x 3200 mhz sticks. they will run 3600mhz , well known best for ryzen. thats all info i have bud good luck for now.
i noticed you said cpu-z isnt showing correct times. could or did you update that to version 1.79 if not do that. older versions are causing problems. ram and sensors. etc.