there appears to have been a temp fix to the one situation where the character
stands after going prone. (All other variations apparently remain untouched).
the temp fix has caused further issues with weapon cycling.

-old-
condition
standing with secondary weapon in hand

event
scroll to primary weapon
change to prone stance
select primary weapon (while animation in progress)

results
primary weapon animation
followed by secondary weapon animation and stops

-new-
stand animation no longer happens
primary animation no longer happens

although the character appears to be holding the secondary weapon
the weapon status indicator shows primary equipped and audio is of primary
(assumed weapon is primary and weapon animation cycling has caused mismatch)

however, returning to standing (directly from prone or from crouch first)
produces a primary weapon animation that doesn't alter equipped weapon state