contrary to what I've read, my attenuation went down from 37db to 32.5db.
Is that with the same router? Sometimes diff routers measure diff attns.
Your line should be syncing about 14 Meg, but I don't like the wide variation in NM over the day. Would not expect much more than 3 dB reduction overnight.
Indicates a wiring issue. Are you plugged into master socket and isolated any extensions?
1999: Freeserve 48K Dial-Up => 2005: Wanadoo 1 Meg BB => 2007: Orange 2 Meg BB => 2008: Orange 8 Meg LLU => 2010: Orange 16 Meg LLU => 2011: Orange 19 Meg WBC