It depends on what the resolution said, the resolution should usually state when the levy is to be due and payable.
Can you provide us with the contents of the resolution?
The strata manager shouldn’t be telling you when the levy should be raised, if the work needs to be done, it needs to be done. Is the strata manager close to the dissenting owner? (not beyond the realms of possibility if he is the former Chairman)
Perhaps you need to make it clear to the strata manager that the wishes of one owner don’t govern how things are to be progressed.