For me as well...
After updating (without any DDU this time) I returned to full refresh rate on the primary monitor and thought to be flicker free. But now I also saw the black lines you mentioned while having the browser open (hardware acceleration turned on since some days) - even though for me it more looks like a black bottom half of the screen or even a full black frame being displayed.
But I can confirm, it's WAY better, but not fully fixed!
For me all problems have been resolved since the latest update. Most problems would occur when I had 2 or more GPU intensive tasks running at the same time or when I would release lots of VRAM etc
Now I can finally play at 240fps and render stuff in the background without getting a seizure. thanks
Purchased a Sapphire Radeon VII last Friday and I am getting flickering at random intervals and driver crashes (but recovers) on desktop while browsing Firefox, Excel, Word ... Strangely I have not had a single crash other than flickering while gaming, even with a undervolt and +150 on HBM. Other than that I have had one occurrence where after stepping away from my PC a bit upon waking up my monitor, the colors were inverted/purple hue, but this was fixed by switching my monitors off and on.
I am using the new 19.5.2 driver and a Startech (DP2DVID2) DP to DVI active adapter on my main monitor (Benq xl2411z - 144 hz) and the DP on my second monitor (xl2420t - 120 hz). I just want to know if this is indicative of a hardware failure or just a bug while I am still in my return window from Amazon... Overall my shot with AMD has not been a pleasant one so far...
I have been having similar issues described as above ever since I upgraded my 2nd display from a 1080p TV to a 4k TCL Roku tv. with an Acer XF270HU for Primary display.
I have a Gigabyte Vega64 Liquid on Win 10 1903. I have had issues on all drivers since last summer. I am currently on 19.2.1.
I have used several different HDMI 2.0 cables to see if cable was bad and had to drop the refresh rate from 60 to 30 otherwise I get very bad artifacting @ 4k 60 during YOUTUBE playback etc. At 30 or 29 hz I get random black screens which is very annoying.
2700X on Asrock X370 Taichi
16GB Gskill F43600C16D GVK
Samsung 970 evo nvme OS drive
The problem is back againt with a Radon VII under Win10 1903.
Driver : Adrenalin 2019 Edition 19.7.1 Optional
This problem has reoccurred since updating to 19.7.1. I did not have this problem on 19.6.x.
Radeon VII on Win 10 1809
Monitors 144hz (1440p) + 60hz (1080p)
I just updated from 19.6.3 to 19.7.2, and I can confirm that the exact same issue is back.
All specs the same as my original post except running windows 10 1903.
All issues are back on 19.7.1, 19.7.2 and 19.7.3 drivers. Also Freesync works only on one(random) connected display now. It worked fine on 19.6.3 with more than 1 displays at the same time.