Howdy,
After dealing with various SWA latency/connection/problem issues for the past several months, based purely on observation and not inspecting code I strongly suspect that script commands are being sent by the browser client to the Server for operations like moving and deleting messages.
This might work fine for a few messages at a time but causes all sorts of problems when attempting to apply an operation against tens and hundreds of messages at a time (eg manually deleting junk mail out of the inbox).
I'm sure all sorts of problems people have posted about in this forum would be addressed if "remoting" or something like that was implemented... ie. instead of individual operations executed by the browser client, a "master command" to code residing on the server be executed instead. By executing the operation entirely on the server, you eliminate network traffic congestion/latency/integrity issues so the result is magnitudes faster than what is happening now.
One approach might be something similar to how IMAP works, initially the User "marks" messages for a later operation, then applies a selected operation against all marked.
Until this fundamental issue causing latencies is addressed, SWA likely will continue to crash, not update completely or at all and may continue to complain about "connection" problems.
Thx.