Lightroom Classic 15.5.1 AI models stuck at 0%, causing Generative Remove and some presets to fail

Lightroom Classic 15.5.1 was freshly installed today after subscribing to Creative Cloud.

Some presets cannot be applied. When I select them, Lightroom displays “Some AI models are downloading. Please try again later” and remains at 0%.

Generative Remove also fails with “Generative Remove Failed.”

Lightroom Classic's Cloud Storage panel also shows “Trying to Connect with Server.”

I tested the issue using both my normal internet connection and a phone hotspot, with the same result. Lightroom Desktop and Lightroom Mobile work normally.

I checked the Windows hosts file and there are no Adobe-related entries blocking Adobe domains.

The standard Remove/Heal/Clone functionality works correctly when “Use generative AI” is disabled.