W56P answering randomly

[DavidDDD]

We have 6 W56P handsets on 2 base stations (3 per base station).
Recently one of them, not always the same one, will auto answer a call on speakerphone. "Auto Answer" is turned off on all the handsets.

The 6 W56P phones, along with 7 desk phones are in the same ring group (6400). In this example one of our handsets on ext 6020 'answered' the call on its own.
"-----KYLE" XXX4208915 [Trunk: vitelity] 8179002000 DIAL 2017-10-16 20:02:24 0:00:00 0:00:00 -
"-----KYLE" XXX4208915 [Trunk: vitelity] 6400 RINGGROUP[6400] 2017-10-16 20:02:24 0:00:00 0:00:00 - Grandstream GXP2160
"-----KYLE" XXX4208915 [Trunk: vitelity] 6010 RINGGROUP[6400] 2017-10-16 20:02:24 0:00:09 0:00:00 - W56P
"-----KYLE" XXX4208915 [Trunk: vitelity] 6021 RINGGROUP[6400] 2017-10-16 20:02:31 0:00:02 0:00:00 - Grandstream GXP2160
"-----KYLE" XXX4208915 [Trunk: vitelity] 6020 RINGGROUP[6400] 2017-10-16 20:02:31 0:00:19 0:00:16 - CALL ANSWERED - W56P
"-----KYLE" XXX4208915 [Trunk: vitelity] 6007 RINGGROUP[6400] 2017-10-16 20:02:31 0:00:02 0:00:00 - Grandstream GXP2160
"-----KYLE" XXX4208915 [Trunk: vitelity] 6007 RINGGROUP[6400] 2017-10-16 20:02:31 0:00:02 0:00:00 - Grandstream GXP2160
"-----KYLE" XXX4208915 [Trunk: vitelity] 6007 RINGGROUP[6400] 2017-10-16 20:02:31 0:00:02 0:00:00 - Grandstream GXP2160
"-----KYLE" XXX4208915 [Trunk: vitelity] 6007 RINGGROUP[6400] 2017-10-16 20:02:31 0:00:02 0:00:00 - Grandstream GXP2160
"-----KYLE" XXX4208915 [Trunk: vitelity] 6007 RINGGROUP[6400] 2017-10-16 20:02:31 0:00:02 0:00:00 - Grandstream GXP2160
"-----KYLE" XXX4208915 [Trunk: vitelity] 6007 RINGGROUP[6400] 2017-10-16 20:02:31 0:00:02 0:00:00 - Grandstream GXP2160
"-----KYLE" XXX4208915 [Trunk: vitelity] 6007 RINGGROUP[6400] 2017-10-16 20:02:31 0:00:02 0:00:00 - Grandstream GXP2160
"-----KYLE" XXX4208915 [Trunk: vitelity] 6000 RINGGROUP[6400] 2017-10-16 20:02:31 0:00:02 0:00:00 - Grandstream GXP2160
"-----KYLE" XXX4208915 [Trunk: vitelity] 6009 RINGGROUP[6400] 2017-10-16 20:02:31 0:00:02 0:00:00 - Grandstream GXP2160
"-----KYLE" XXX4208915 [Trunk: vitelity] ]

Note the duration for ringing desk phones is 2 seconds, except the W56P phones. Ext 6010 is a W56P, didnt answer, but shows 9 seconds duration.