You perhaps need to readjust -dcri for ETH-only mode, use "+" and "-" keys for that and "s" key to see current speed. You can also try "-asm 2" option with various -dcri to see if it is faster.
Thank you @AnViGo and @Claymore
I use this:
-powlim 15,15,15,15,15,15 -cclock 1150,1150,1150,1150,1150,1250 -mclock 2050,2050,2050,2000,2050,2100 -tstop 85,85,85,85,85,85 -tt 64,64,64,64,64,64 -fanmin 30,30,30,30,30,30 -fanmax 100,100,100,100,100,100 -asm 2
I see that -dcri default is 30.
On v11.0, any value of -dcri between 20 and 90 keeps the hashrate very very similar as -dcri 30 (around #0 29.7 / #1 28.6 / #2 30.

On v11.2, -dcri 30 keeps the hashrate 2MH/s lower and increase while I increase -dcri
Between -dcri 40 and 80, it increases 0.1~3MH/s on each gpu (around #0 29.8 / #1 28.9 / #2 31.0) and 2 GPU hangs 2 times while I was typing this post
Any idea what I can do to increase it a little bit?
Thanks in advance!