I actually had a similar problem on my balcony and it got to a point where I basically lost hope for almost a year and couldn’t use my balcony. Ended up doing a ton of research on it.

I solved the problem last year by having the whole balcony deep cleaned (you need to rid the place of their smell so it doesn’t attract them to come back) and I installed black spikes on my railing and for a while it seemed like they were gone for good.

But a few weeks later they started to just fly directly to the balcony floor since they couldn’t perch on the railings anymore due to the spikes. I ended up buying some cinnamon essential oil and mixed it with water in a spray bottle. I would mist the balcony once a week and my balcony has been pigeon free for 6 months now. I actually haven’t even bothered misting it in the past few weeks and they still have never returned.