Sync drop

For months, I think the beginning of the year I have had a downstream sync of 79999 but today I had a resync. Admittedly I was running a downstream SNRM of 0.8db with attainable of 73999. Today after the resync I am now syncing at 66799 @ 3.4dB. Here's my stats :-

adsl info --stats
adsl: ADSL driver and PHY status
Status: Showtime
Last Retrain Reason: 0
Last initialization procedure status: 0
Max: Upstream rate = 14675 Kbps, Downstream rate = 67327 Kbps
Bearer: 0, Upstream rate = 14675 Kbps, Downstream rate = 66799 Kbps
Bearer: 1, Upstream rate = 0 Kbps, Downstream rate = 0 Kbps
Link Power State: L0
Mode: VDSL2 Annex B
VDSL2 Profile: Profile 17a
TPS-TC: PTM Mode(0x0)
Trellis: U:ON /D:ON
Line Status: No Defect
Training Status: Showtime
Down Up
SNR (dB): 3.3 6.2
Attn(dB): 20.0 0.0
Pwr(dBm): 12.6 7.4

VDSL2 framing
Bearer 0
MSGc: -6 26
B: 243 237
M: 1 1
T: 0 64
R: 10 16
S: 0.0000 0.5159
L: 17470 3939
D: 8 1
I: 254 127
N: 254 254
Q: 8 0
V: 0 0
RxQueue: 76 0
TxQueue: 19 0
G.INP Framing: 18 0
G.INP lookback: 19 0
RRC bits: 0 24
Bearer 1
MSGc: 154 -6
B: 0 0
M: 2 0
T: 2 0
R: 16 0
S: 6.4000 0.0000
L: 40 0
D: 3 0
I: 32 0
N: 32 0
Q: 0 0
V: 0 0
RxQueue: 0 0
TxQueue: 0 0
G.INP Framing: 0 0
G.INP lookback: 0 0
RRC bits: 0 0

Counters
Bearer 0
OHF: 0 225338
OHFErr: 0 1
RS: 63647560 1528273
RSCorr: 3876 1
RSUnCorr: 0 0
Bearer 1
OHF: 115735 0
OHFErr: 0 0
RS: 1156731 0
RSCorr: 0 0
RSUnCorr: 0 0

Retransmit Counters
rtx_tx: 30951779 0
rtx_c: 5 0
rtx_uc: 0 0

G.INP Counters
LEFTRS: 0 0
minEFTR: 66809 0
errFreeBits: 1894318 0

Bearer 0
HEC: 0 0
OCD: 0 0
LCD: 0 0
Total Cells: 238806507 0
Data Cells: 252989 0
Drop Cells: 0
Bit Errors: 0 0

Bearer 1
HEC: 0 0
OCD: 0 0
LCD: 0 0
Total Cells: 0 0
Data Cells: 0 0
Drop Cells: 0
Bit Errors: 0 0

ES: 0 1
SES: 0 0
UAS: 37 37
AS: 1860

Bearer 0
INP: 52.00 0.00
INPRein: 1.00 0.00
delay: 0 0
PER: 0.00 8.28
OR: 0.01 30.89
AgR: 66867.61 14706.05

Bearer 1
INP: 4.50 0.00
INPRein: 4.50 0.00
delay: 3 0
PER: 16.06 0.01
OR: 79.68 0.01
AgR: 79.68 0.01

Bitswap: 372/372 8/8

Total time = 31 min 37 sec
FEC: 3876 1
CRC: 0 1
ES: 0 1
SES: 0 0
UAS: 37 37
LOS: 0 0
LOF: 0 0
LOM: 0 0
Latest 15 minutes time = 1 min 37 sec
FEC: 243 0
CRC: 0 0
ES: 0 0
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
Previous 15 minutes time = 15 min 0 sec
FEC: 1949 1
CRC: 0 1
ES: 0 1
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
Latest 1 day time = 31 min 37 sec
FEC: 3876 1
CRC: 0 1
ES: 0 1
SES: 0 0
UAS: 37 37
LOS: 0 0
LOF: 0 0
LOM: 0 0
Previous 1 day time = 0 sec
FEC: 0 0
CRC: 0 0
ES: 0 0
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
Since Link time = 30 min 59 sec
FEC: 3876 1
CRC: 0 1
ES: 0 1
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
NTR: mipsCntAtNtr=0 ncoCntAtNtr=0
>

Anything I can do? Seems a heck of a drop after 1 resync. Tried swapping the modem for another ZyXEL VMG-1312-B10A but same sync.

SNRM of 0.8db with attainable of 73999 and a drop to 65799 at 3.4dB looks sensible, suggesting modem was hanging in on a very thin thread for a while.

As for why, without access to lots more hardware and logs impossible to tell what is the cause, could just be more people ordering VDSL2 in the area

At first I thought G.INP had turned off because when I first got the line enabled it was syncing around 66 without G.INP. But according to the stats G.INP is Enabled.

Sounds like a new crosstalker came online today.
It dropped your snr so low it caused a resync.

Looks like that crosstalker has taken about 8Mb off your line.