I've had this problem... it's a fine line between holding it for about 1 sec to open trunk and longer for alarm. I just go open the trunk with my hand now vs using the remote. My wife's 535xiT does the same thing with remote trunk release... pain in the butt.
17 Tesla Model X 90D
16 BMW X1 Med Blue/Oyster (Hers)
PAST: 14 Tesla Model S P85D, 13 X5 M-sport, 04 M3 Cab, 08 E92 M3, 08 535xiT, 07 X5 4.8i, 06 E90 325i, 87 E30 325i, 85 E30 318i