Blueprint import 'unknown command'

Tags: #<Tag:0x00007fc4327c2ce0>

I have tried to import several blueprints from the exchange and when I click ‘preview’, I get an ‘Unknwon command’ red text and the screen stays there.
It happens with both methods: importing them with the new badges or copy pasting the URLs. It happens with all of them, I have not been able to import just a single one.

Logger: homeassistant.components.websocket_api.http.connection
Source: components/websocket_api/connection.py:84
Integration: Home Assistant WebSocket API (documentation, issues)
First occurred: 8:02:20 (2 occurrences)
Last logged: 8:02:22

[2699047504] Received invalid command: blueprint/list
[2699047504] Received invalid command: blueprint/import

Any idea which could be the root cause?