Speedtests on Sagemcom using wired ethernet speeds are crippled

Update: I finally called T-Mobile Internet support.  After I described the fact that WiFi was significantly faster than ethernet with the Sagemcom the agent went away for awhile.  When he returned he said that it was a defective modem and they would issue a warranty replacement.  However, the replacement would be with an Arcadyan KVD21 Gateway (which he said is newer than the Sagemcom).   I'll post an update when I receive and install the Arcadyan KVD21 Gateway.