Does the CUCM version in CER say "14" or "14.0"? I've run into a bug where the version was set to 14 and had to be changed using the GUI to 14.0. Your log should also reflect that slight difference.
How did you upgrade the phones? That version of firmware for those phones was the base firmware of an older devicepack (https://www.cisco.com/web/software/282074299/124017/cmterm-devicepack10.5.2_12014-1_Release_Notes.pdf)I suggest following the ins...
Jabber clients using MRA will work in an environment with AnyConnect VPN. MRA will allow user 1 to use collaboration infrastructure without VPN, but he/she may need VPN for other use cases like network drives and such.If user 2 connects to VPN first...