Agree with the others. Coco's recall went to pot completely at 7 months for about 5 months - she drove me mad.
I don't think a behaviourist would really have made that much difference tbh - I really think it is just something you need to persevere with and sadly there is no quick fix - go back to basics, whistle training, high value treats, long line etc etc. I was frequently almost in tears with frustration when she just would not come back to me - or rather she would come back but just stayed out of reach so I couldn't get her lead on, she even went running out of the park after a loose dog across the road - I nearly wet myself that time
I just learned to work within her limitations - ie when she was so unreliable I only let her off lead in a secure place where there were not too many distractions and carried livercake, squeaky toy, anything that she found interesting and just stuck at it. Don't listen to what other people say is 'normal' - all dogs are different and you will get there. It seemed to go on forever but eventually at about 13 months, I suddenly realised that she was recalling pretty well and walks went back to being enjoyable
She is far from perfect now but she is a million times better than she was.
If I was to do it again I would try not to stress too much, use a long line if there are a lot of distractions, bake lots of livercake and just allow plenty of time for walks. I now realise that training recall is an ongoing thing - Coco is now 3 and a half I still practise it with her on every walk
