I don’t think that it is (directly) related to power saving mode.
I can walk to the charging station, pinging continuously, and watch the RSSI icon at the top of the screen reduce and die, and watch the pings go from working to “Destination Host Unreachable” to “Network is unreachable”.
I can walk to the charging station, scanning the actual RSSI number continuously, and watch it progressively lower until, apparently, the signal is no longer viable.
Doing either of those things should keep the WiFi card and other relevant components from power saving.
I can accept that perhaps the signal at the charging station was always marginal but it does seem as if it has become weaker.