Inband SNR Status is 'Poor' on some TV channels

[ron5151]

Sorry for the long post, but I think more details may be helpful.

I have FIOS service with two VMS1100 STBs, 300 Mbps serice one CR1000B router and one E3200, two switches, several wired PCs, and several wireless laptops, phones, tablets, DVD players, etc.

The TV attached to STB#2 has been experiencing picture quality issues. They include picture freezing for >30 seconds, intermittent bad pixel blocks, and sometimes a blank screen. Both picture and sound are affected. A reboot of STB#2 generally helps for a couple of days, but then the problem reoccurs.  I've gathered some data from the System Diagnostics page that is shown below. 

For STB#1 (The good one)                                       

Channel Number                       6            10           47           150

Channel Frequency            543         543        465        693

Inbound SNR Level               39.5       39.5       37.5       40.5

Inbound SNR Status           Good     Good     Good     Good

Inbound Per Level                     -5            -5            -8            -3

For STB#2  (The one with issues)                                      

Channel Number         3                  6              10            47           163        506        547        763        795

Channel Freq               543          543        543        465         453         459        537        249        261

Inbound SNR Level  29.8       27.9       28.4       37.3        36.8       38.2        40           31.3       32.6

Inbound SNR Status Poor      Poor       Poor     Fair       Good     Good     Good     Fair      Fair

Inbound Per Level        -9                 -9            -9            -12             -11             -11          -9            -19          -18

Additionally, STB#2 Channels 3, 6, and 10 had ShortTerm Error Counts of    0,  153,110 and  153,110 respectively. 

Summary:  STB#2 has issues on some SD Channels.  The HD channels are fine. The Inbound SNR Level on STB#2 is about 10 db lower than STB#1 , but only on some frequencies.  On stb#2, many of the TV channels (freq 543) have poor snr.  But the channels on the other frequencies are good The issue seemed to start when I upgraded from 100 Gbs to 300 Gbs service  with new routers. All coax connections are tight.

I contacted Verizon support and they want me to upgrade to VM4100 STBs.

Any help is appreciated.

Thanks,  Ron