Had a similar experience through Asia when I was still *S (i.e. no status).

Same day flight
SIN-BKK (J Class) - Lounge access in SIN permitted
BKK-LAX (PE Class) - Lounge access in BKK not permitted

Return flight
LAX-BKK (PE Class) - Lounge access in LAX not permitted (no love lost)
BKK-SIN (J Class) - Lounge access in BKK permitted (great for a nice shower)