Spark 2.6.x Authentication with server fails. Why?

I have been using Spark 2.5.8 to connect to my company’s IM server with no problems for a long time. Recently I installed Spark 2.6.3 and entered my login information and confirmed that the Preference settings were identical to those used for Spark 2.5.8.

When I attempt to login using Spark 2.6.3 it always fails due to an Authentication failure.

Spark 2.6.3 sends the following initial packet:

<stream:stream to=“stiletto” xmlns=“jabber:client” xmlns:stream=“http://etherx.jabber.org/streams” version=“1.0”>

Z2xlbm5cNDBzdGlsZXR0b1wyZnNwYXJrAGdsZW 5uXDQwc3RpbGV0dG9cMmZzcGFyawAxMjgtd255bSs2ODk=

Spark 2.5.8 sends the following initial packet:

<stream:stream to=“stiletto” xmlns=“jabber:client” xmlns:stream=“http://etherx.jabber.org/streams” version=“1.0”>

AGdsZW5uADEyOC13bnltKzY4OQ==

The SASL Authentication packet is very different. Why. Is there a way to make Spark 2.6.3 work with our IM server?

I can findout what IM server we are using if necessary.