It might be possible the channels ramp up (sync up) as the need arises.(on demand type of bandwidth scaling)
Called adv support team and they said "there is signal leakage from the street to the pillar"
Potentially try the following when testing while the linksys is connected, turn off the wifi part. And see whether the wire connected workstation will once again reach near 800 in transfer.
Does the desktop have wifi capabilities, turn wifi off if it does.
The priority wifi over wired is a user specification. When both are active, sone think the wired will be preferred. While common, have seen when the wifi took precedence.
‡Maximum Performance derived from IEEE Standard 802.11 specifications. Actual performance may vary, including lower wireless network capacity, data throughput rate, speed, range and coverage. Performance depends upon many factors, conditions and variables, including building materials and construction, volume of network traffic, mix of wireless products used, interference and other adverse conditions. In order to achieve the best performance, this product must be used with compatible AC2200 wireless devices. The standard transmission rates for each node—867 Mbps (for each 5 GHz radio), 400 Mbps (for 2.4 GHz)—are the physical data rates. Actual data throughput will be lower and may depend on the mix of wireless products used and external factors