Chromebook Tab 10 D651N WiFi Connection Problems

I've been evaluating one of your Model D651N Tab 10s for a client planning a bulk purchase of multiple tablets for their employees.

The Chromebook approach in a tablet has worked well except for one major concern.  WiFi connections have been erratic.  Speeds on several 802.11n 2.4 and 5 GHz channels are acceptable after initial connection but will degrade.  Typically after 15 to 30 minutes.

This degraded speed condition occur in spite of changing the advanced setting for WiFi to always remain "on".  WiFi will still disconnect after a period of sleep.  Also known WiFi networks will act forgotten or require re-entering password when needing to reconnect.  The "always on" was one of my first steps at troubleshooting.

It also occurs regardless of application (Android or Chrome) or website that's running.  Verified by LAN and WAN speed tests that were in a normal 10+ Mbps range that then degraded to a maximum of around 1 Mbps.  Signal strength at a typical site remained in the -55 to -75dBm range.

There is little SSID conflict from external sources in this location.  Only two internal ones that can establish a connection.  They do happen to be secured using WEP not WPA.  Also with minimal WiFi and internet traffic from other devices, there seemed no apparent relationship to the tablet's connection problems.  Other WiFi devices (phones) at the same location connected on the same channels and SSIDs exhibited none of the same connection problems. 

The frustrating part overall is "typically" and "usually".  No hard and fast conditions presenting clues to the exact cause.  The best solution when using is to completely power off, wait, restart the tablet, and then reconnect WiFi.  Turning WiFi off and reconnecting also works sometimes.

The tablet either does not, or has difficulties switching to a higher-power SSID when the current connection's strength becomes unacceptably low.  But avoiding that situation does not seem a viable solution for users.

The Chrome OS update (now 76.0.3809) did appear to improve WiFi connectability somewhat which raises a suspicion whether these erratic WiFi problems are software or hardware related.    Powerwashes and hard resets do not change the connectability.

Your comments and recommendations would be appreciated.  A solution or a workaround is needed  for these tablets to be acceptable in the intended use.