Be patient. They may be putting on a lot of root growth and next year is when they will take off and start giving you fruit. The best thing you can do for them now is to clear out the competition and mulch them good. I have also found that drilling holes in the ground (a garden hose with a pressure nozzle works great) and filling them with rotting wood and some biochar helps a lot. I planted some new raspberry vines last year and didn't get any fruit the first year, but this year I got a decent amount of berries. And they are propagating and starting new canes.
And if its any consolence, mine didn't do so good last year and thats when i planted them. but this year they have become like triffids!! i have had that many they are coming out of my ears through mulching and i don't know if the companion planting also helps but i have heard that it helps. i have mint and i am going to put some garlic and wild ramsons under mine with daffodils
To echo the others, I planted a patch of Anne golden raspberries last spring. They grew fairly well and produced some berries very late in the season but there were just a couple of canes per plant. I mulched with woodchips and later on with grass clippings and the variety of weeds that sprouted in the cleared area of lawn where the berries were planted. I let any legume-type weeds stay. Fast forward to this June, the white sweet clover (Melilotus alba) was over three feet tall and so intergrown with the forest of canes it was amazing to me. I can't claim any credit for planting the sweet clover- it was already in the soil seed bank apparently. The sweetclover has been chopped and dropped three times this season and the canes have exploded in size and sheer numbers. There is virtually 100% canopy closure in the patch and it is impossible to tell where the original raspberry crowns were planted they've suckered so much. The sweet clover did not appear to be any competition for the raspberries, just jacked up their growth. The canes are now flowering and stand between four and feet tall (1.25 & 1.6m). Keep the competing vegetation next to your berries down, mulch with something that will build soil and keep them watered. You'll likely be pleased with the result next season.
The biggest boost I have found for berries is to innoculate their soil with a bit of spruce forest litter. This is where berries thrive in my local wild areas, and so I figure there is some symbiotic relationship between the conifer duff and the berries.
I would also add that plastic containers arent really the ideal setting for berry roots, who want lots of air in the soil, and mositure but not wetness. With plastic containers, it is easy to have wet or dry, IMHE, but evenly moist seems more challenging. This is another reason why the conifer compost mulch is helpful I would guess, keeping the soil moist but not wet.
I disliked potting them but had to keep them at the rental where I could water them. Now I have water on my land and I won't have to do that again. My grapes and currants suffered because of that as well.