The standard Lightning heavy attack consists of 3 damage 'ticks' then 1 final hit, which make up the full heavy attack channel.
On PTS this has been changed to only 2 'ticks ' plus the final hit.
No mention of this in patch notes or any explanation for the change.
As someone who, like many, have disabilities or restricted use of hands the lightning heavy attack style was favoured by myself for its simplicity.
You said that ' you had not forgotten HA builds ', is this what we get, a silent 25% nerf ?
PTS - 2 damage ticks;
LIVE - 3 damage ticks