How to properly interpret netstat RX-DRP column?

We have a couple of Zotac mini PCs that we have installed at remote locations. One customer seems to be having network issues - we're not sure. It seems to be one of those ghosts in the machines. The ethernet port is lit with yellow on the left side, green on the right. Usually that would tell me that the connection is less than 100M but according to the connected switch and the output from 'ethtool', a utility I'm not that familiar with, we are connected at gigabit speed. Maybe that is what the yellow means? Anyway, a possibly related question regards the RX-DRP column. Why does this column have a value when the networking switches, etc say that there are no dropped packets or connection problems?

Iface             MTU    RX-OK RX-ERR RX-DRP RX-OVR    TX-OK TX-ERR TX-DRP TX-OVR Flg
enp2s0           1500        0      0      0 0             0      0      0      0 BMU
enp3s0           1500  2513963      0  35220 0       1329805      0      0      0 BMRU
lo              65536     1693      0      0 0          1693      0      0      0 LRU
wlp1s0           1500        0      0      0 0             0      0      0      0 BMU

Here is the output from 'ethtool'

Settings for enp3s0:
        Supported ports: [ TP MII ]
        Supported link modes:   10baseT/Half 10baseT/Full
                                100baseT/Half 100baseT/Full
                                1000baseT/Half 1000baseT/Full
        Supported pause frame use: No
        Supports auto-negotiation: Yes
        Supported FEC modes: Not reported
        Advertised link modes:  10baseT/Half 10baseT/Full
                                100baseT/Half 100baseT/Full
                                1000baseT/Full
        Advertised pause frame use: Symmetric Receive-only
        Advertised auto-negotiation: Yes
        Advertised FEC modes: Not reported
        Link partner advertised link modes:  10baseT/Half 10baseT/Full
                                             100baseT/Half 100baseT/Full
                                             1000baseT/Full
        Link partner advertised pause frame use: No
        Link partner advertised auto-negotiation: Yes
        Link partner advertised FEC modes: Not reported
        Speed: 1000Mb/s
        Duplex: Full
        Port: MII
        PHYAD: 0
        Transceiver: internal
        Auto-negotiation: on
        Supports Wake-on: pumbg
        Wake-on: g
        Current message level: 0x00000033 (51)
                               drv probe ifdown ifup
        Link detected: yes

I'm just trying to understand something I didn't before and get a customer back to running at full speed here. Any insight at all is appreciated.