@dgilbert2 - No, G.INP does not have to be enabled first to attain 3 dB. However, looking at the current state of your line and errors then you are probably not going to attain it in its current state without G.INP.
It absolutely does.
DLM will not lower the target snrm to 5dB until the line has retransmission (G.INP) applied 1st.
All lines run with a 6dB target snrm by default.
Within a couple days of retransmission being applied if the line is stable enough DLM will try 5dB.
A couple of days later if the line is still stable it will drop to 4dB.
A couple days later it will drop to 3dB.
I've never seen a line with a lower target snrm without retransmission.
We see plenty lines sitting at 3dB without retransmission, but the target snrm is still 6dB. They will have synced at 6dB and then dropped down.
There's dozens of reasons that can cause a lines snrm to drop below the target like that.
DLM always drops the target snrm in 1dB increments. It will never jump from 6dB to 3dB.