For time frame identification...when did you pitch the yeast?
It is quite common for a wine to be cloudy even when it initially hits the dry mark. I would keep it topped up, rack it off sediment as it drops every two months, and park it somewhere that the temperature is at least ten degrees lower. Cooler temp will clear a hazy wine PDQ. But you want to attempt to degas this wine before you drop the temp on it....cooler temps and degassing do not like each other.
The pectinase as long as added while ferment is still active, ie not yet dry, will still do its thing; otherwise it just drops out with sediment. Of course the way you prepared your must can impact a haze, ie if you steep your fruit in hot water this will many times set the pectin making it more troublesome to clear.
I am pretty confident that given time and a cooler environment this will clear. Plum typically needs aging anyway, so time is your friend. If push comes to shove you can look at finings like SuperKleer or isinglass, etc.
