It looks like Ba9 left the gate at 16:30 which in the grand scheme of things at LHR I define as on time.

DOBA9/06JAN
* OPERATIONAL FLIGHT INFO * BA 9 0 SA 06JAN18
CITY INFO HOUR (LOCAL)

LHR ESTIMATED TIME OF DEPARTURE 1630
LEFT THE GATE 1630
ESTIMATED TIME OF ARRIVAL 1017 BKK
*1A PLANNED FLIGHT INFO* BA 9 0 SA 06JAN18
APT ARR DY DEP DY CLASS/MEAL EQP GRND EFT TTL
LHR 1505 SA JCDRIWETYBH/M 777 11:20
KMLVSNQOG/M

looks like a knock on effect of about 30 mins delay so far for your flight tomorrow :

DOBA10/07JAN
* OPERATIONAL FLIGHT INFO * BA 10 1 SU 07JAN18
CITY INFO HOUR (LOCAL)

BKK ESTIMATED TIME OF DEPARTURE 1147
ESTIMATED TIME OF ARRIVAL 1757 LHR
*1A PLANNED FLIGHT INFO* BA 10 1 SU 07JAN18
APT ARR DY DEP DY CLASS/MEAL EQP GRND EFT TTL
BKK 1115 SU JCDRIWETYBH/M 777 13:10
KMLVSNQOG/M