RSS feed very slow

I have two blogs (same theme, plugins, host) – one is fine and the other is very slow. For the slow feed – the RSS widget does not work to get the feed on my sidebar.

The slow feed is: https://www.noiseexpert.com – noiseexpert.com/feed/
The fast one is: https://www.aiofinancial.com – aiofinancial.com/feed/

I’d appreciate any thoughts. Thanks