Do not use iGPU with AMD! Bad idead, it blocks OC settings, might be fixed with newer drivers, but it was big problem for most cards for mining. Only with Nvidia cards.
Could you please elaborate on this? I'm using onboard intel graphics on all my rigs, both amd and nvidia, and I did have some issues with amd systems, but have always just assumed that it's due to their buggy drivers and all the nonsense with modded bioses, paching etc. I've only got one rig with amd cards that doesn't use onboard graphics, and it is indeed the most stable among them all. So now your post made me think that maybe I should try disabling the onboard on all my amd rigs. OC settings don't seem to be blocked though, I'm using overdriventool and it works fine.
They might fix it. I'm still on 17.6.2 drivers and on these and older ones there were problem with stability and OC settings, clocks weren't successfully applied when you check it with Hwinfo and GPU-Z. Some of my customers have same problems with newer drivers too, but not sure about Adrenaline.
Hmm... I just switched my (3) RX 560 rig over to mining UBQ to check this out and I'm getting 38.8 MH/s total with 1200/1900 set in MSI AB. Driver version is Adrenalin 18.2.2 in Compute mode. So my speed does seem a bit low per card (12.9 MH/s) given they all have Elpida memory. Not using the iGPU is a bit of a problem with the Onda D1800 mining mobos, though.
EDIT - and dropping all 3 mem clocks to 1800 did not change hashrate as it should have...
You probably need better timing strap. Also it's better to change clocks before you start mine it sometimes doesn't react on changes.