I did not post the query as I can't post it as is and what I can post might not be useful at all. Find below a query with renamed tables/columns. I only posted this in case someone else comes across this problem as I've already found a workaround.

SELECT

A.a_id,

C.c_id,

B.b_id,

D.d_id,

E.e_id,

F.g_id

FROM table_G G

INNER JOIN

table_A A

ON A.a_id = G.a_id

INNER JOIN

table_C C

ON C.c_id = G.c_id

LEFT JOIN

table_B B

ON B.a_id = A.a_id

LEFT JOIN

table_D D

ON D.b_id = B.b_id AND D.c_id = G.c_id

LEFT JOIN

table_E E

ON E.e_id = COALESCE(D.e_id, C.e_id)

LEFT JOIN

table_F F

ON F.g_id = G.g_id

WHERE

F.g_id IS NULL

AND A.created < DATEADD(dd, DATEDIFF(dd, 0, GETDATE()), 0)

The problem line I spoke of was "AND A.created ..." - table Table_A contains around a million records. Simply removing that line worked and putting the "DATEADD(dd, DATEDIFF(dd, 0, GETDATE()), 0)" into variable and using variable instead also worked.