Hey Rockey,
The following is my timeline.

Applied on 31st July.
Biometric done on 18th August.
received a letter saying complex issues on 18th September dated 12th September .

will appreciate if you guys also share your application time line.

Many thanks

Hello mate,
Myself also got the same kind of letter on 18th of Sept. dated 12th of Sept. After this no update till. Two of my friends have also got the same kind of letter.