Thanks for your comments @RobbieMac
I do lose my internet connection on an almost daily basis. This happens 2 or 3 times a day on a fairly regular basis.
I'm not sure what speed the connection re-syncs to after a drop-out but will check my speed next time it happens.
No problem @MikeG2606
From the looks of it, it's DLM doing what it's suppose to. Stability is always preferred over speed and that's why the higher SNR is being set to reduce the downstream. In your case it's just a vicious circle and we'll need to tackle the drops and in turn, the speed will sort itself out.
I have sent you a private message with instructions on how you can send us over your details and we'll look into this for you. See: Private messages