Major problem: Plants not growing, others bolting already

My wife and I put nearly two cubic yards of composted mushroom manure on our Vancouver garden in February and dug it in a little bit.

We have purchased manure from the same mushroom farmer numerous times before.

What I thought was weird this year though, was that while waiting for the weather to warm up and the ground to dry somewhat, over March and April I noticed that no weeds were popping up and the over-wintering plants we had put manure around were not showing any sign of benefiting from the manure.

We thought maybe that the manure was not composted enough though it didn't look or smell any different than before.

I added well composted compost and mixed it with the manure and garden soil when we planted over two weeks ago and seeds are barely sprouting. Baby plants such as kale and gai-lan and celery that we transplanted are not showing any sign of growing and in fact, the baby gai-lan has started to show signs of maturing.

The whole thing is just really weird. We have been gardening on this site for 21 years. We once lived up the coast and gardened there too, so we're not new at this, but we're baffled.

Does this sound like the manure was not sufficiently composted?