Hi,
I have recently upgraded from copper to fibre and speeds have gone backwards also, currently getting 3mb which can dip to 2.5mb during the evenings. I live out in the sticks so I am not expecting amazing speeds but would expexct to be getting more than 3mb and think needs looking at as the line in to the house was installed just over 2 years ago so cant be na issue there. I have logged into the router and its confirmed as VDSL:
Line Quality
Upstream line rate (kbit/s): 889
Downstream line rate (kbit/s):3077
Upstream noise safety coefficient (dB): 6.1
Downstream noise safety coefficient (dB): 6.3
Upstream interleave depth: 1
Downstream interleave depth: 1
Line standard: VDSL2
Upstream line attenuation (dB): 17.8
Downstream line attenuation (dB): 30.8
Upstream output power (dBm): 0.4
Downstream output power (dBm): -7.9