A shrub requires time to establish a sturdy -- and vigorous -- root system before it can put out new growth topside.

Various possibilities why "no growth" -- among them insufficient water and/or insufficient light.

What is the "ground cloth?" If plastic sheeting, it's a serious mistake. Even if a woven material, know that you will eventually rue the day you installed it.

People usually use landscape fabric of one kind or another in the hope of avoiding weeds. But weeds will blow in and grow in the mulch that's on top of the landscape fabric.

Suggest you bite the bullet, remove the ground cloth, then stroll the garden now and then as you remove the young weeds before they get out of hand.

About 45 years ago I planted several hundred rhododendons and azaleas using a plastic landscape barrier covered with pine bark nuggets. I had worked the soil and removed many stones before putting down the plastic barrier. I poked holes in the plastic to plant the rhododendrons and azaleas. I was skeptical about whether the plants would get too dry. I was amazed when I saw the results. During droughts, the ground remained moist. During very wet periods, the soil didn't get too wet. The plastic tempered the moisture and seemed to keep an ideal level of moisture. This area was sloping so water never stood on the plastic. The plastic had tiny holes so that some water could get through. The beds were about 6' wide so that there was always moist soil nearby. I was actually very amazed they my lazy side had done something that may have actually be really good for the plants. The plastic is still there after 45 years. The rhododendrons and azaleas have done extremely well, at least until deer attacked them. Then after we put up a deer fence, the ones that hadn't died recovered beautifully.

I would do it again, at least on sloping areas. More recent plantings were done using several sheets of newspaper under pine bark nuggets. That works well also.

Getting back to the original posting, slow is good as long as the plants look healthy. Plants in full sun will grow slower. Those in shade will grow faster but may not bloom. If the leaves are a healthy shade of green with no yellowing, then there are probably no big problems. The most common problem is improper planting. That is when a potted plant is planted without opening up the root system. This will retard growth of the plants and can eventually kill them. The roots that are circling each other strangle each other and the plant dies. If you did that, you may dig them up and replant them correctly. Now would be a good time. Rare Find Nursery has a great instruction sheet on doing this. The link is below.

Here is a link that might be useful: How To Plant (Rarefind Nursery)

Azaleas need an acidic soil, so that could be an issue as well. I don't think the ground cloth would be a problem; most landscapers use them. You will also want to ensure you are pruning them correctly and they are getting the proper amount of light. Your azalea may need to be pruned back hard according to the directions at the top of the following page, which is on rhododendrons, but for which the care is basically the same.

Here is a link that might be useful: Care for Azaleas & Rhododendron