Blocade box and friendlies

[DodgyDave]

ok as England in war with Turkey, i moved a corps to Greece, to force out the Turkey transportfleet, which is blocaded by 2 spanish and 1 english light fleet, i win over the corps present and take the city as well, leave 1I garrison.

note, the turkey fleet moved and died, before next land phase!

At my next land phaze, i want to place a depot here, so i dont need a fleet anymore, but i am not permitted, because the spanish is still blocading the city?

But in normal boardgame rules, the spanish fleets was suppose to leave blocade box, as i owned the city right now. rule 6.2.7.2 also its your enemies who normally can blocade your supply line, not neutrals or friendlies