The OP disappeared but this case for another Hackney location was won at the tribunal yesterday with the same sign issue.

Case reference 2250202096
Appellant xxxxxx
Authority London Borough of Hackney
VRM LV61 YEG
PCN Details
PCN QZ20469461
Contravention date 11 Jan 2025
Contravention time 14:16:00
Contravention location Dunston Street
Penalty amount GBP 130.00
Contravention Parked - place not designated for class of vehicle
Referral date -
Decision Date 21 Aug 2025
Adjudicator Andrew Harman
Appeal decision Appeal allowed
Direction cancel the Penalty Charge Notice and the Notice to Owner.
Reasons The contravention alleged in these proceedings is that this vehicle was parked in a parking place not designated for that class of vehicle: on the council's case it, not being a motorcycle, was parked in a parking place for the use of motorcycles only.
On the appellant's case the sign was unclear. I agree with him. It may well be compliant, but it seems to me that it can be read as allowing both motorcyclists and, separately, J permit holders to park in this bay. I am not satisfied that the sign makes it clear that only motorcycles covered by a J permit can park on it. The appellant as a J permit holder in my view was entitled to conclude that he could park on the bay. I am not satisfied against this background as to the clarity of signage, and I accordingly find that the contravention did not occur.