iOS 26 developer beta download stops at 8.62GB

I have an iPhone 16PM on iOS 18.5 and I got the iOS26 developer beta. When the download starts it always stops at 8.62GB and does not go any further. I have tried resetting the settings, deleting the update and restarting it, using different wifi and they all start downloading and at 8.62GB it stops again. I have over 100GB free space.

What could be wrong?