What does it do? Does it start to download or does it not even download at all? Also are you using win10 or 11?
Does it give any error alerts or anything? Proton is a bit slow in the download I noticed, maybe its timing out? Does it reach a certain percent download? I just install opera and so far downloading. But mine's brand new and up to date. Maybe update your browser or I hate to say this, try a different browser?