No custom artwork in HTML5 Player

Hi there!
I have an issue regarding the artwork.
I’ve uploaded a 1500×1500 artwork for the feed but it doesn’t show in the HTML5 player.
This is the URL for an episode:
https://www.elimoradea.ro/podcast/povestea-lui-melody/

This is the feed url: https://www.elimoradea.ro/feed/podcast

I’ve tested the feed using castfeedvalidator.com and the artwork seems ok.

Thanks!