Your photo shows the bay is incorrectly marked. There is only a single dashed line perpendicular to the kerb whereas it should be a double-dashed line to mark the divide between two bays with separate restrictions. Best practice is also to have the two bay signs on a single pole mounted along side each other with arrows to indicate applicability.
This argument will be totally lost on the council, who anyway, will issue a Fob-Off letter no matter what you say in any informal challenge you submit, so you'd likely have to take them to London Tribunals. This means waiting for the Notice to Owner, and submitting a formal representation.
We always recommend submitting reps to a PCN rather than just coughing-up, as councils can make stupid mistakes in their replies, and it gives time to investigate the matter. GSV shows this as a relatively new m/c bay, as it's not there on the 2021 view.