Thanks. Also, a few more pieces of info - I am running OS 2.9.1, using an iPhone X on iOS 12.1.1 and using the latest C4 iPhone app. The same issue exists when I use the Control4 for PC-Mac application, but when I use Composer HE to control those newer dimmers, they dim perfectly every time.
I'm not sure how to generate the HEX code you mentioned, but the Lua Output window for a dimmer that isn't responding from the iOS app is:
Function: ReceivedFromProxy (5001, RAMP_TO_LEVEL):
dimmer ExecuteCommand function called with : LIGHT_LEVEL
Function: SendToProxy (5001, LIGHT_LEVEL):
Function: SendToProxy (302, MATCH_LED_STATE):
Function: SendToProxy (1, RAMP_TO_LEVEL):
Function: SendToProxy (300, MATCH_LED_STATE):
Function: SendToProxy (301, MATCH_LED_STATE):
dimmer ExecuteCommand function called with : EXTENDED_GET
Thanks for all the help.