“Take note of "It may not work well with smartphones or other Micro-USB chargers/power supplies" in the description. No idea where the blame lies but it just didn't work with the charger I was trying to use (not an official one) into a 4B. Swapped to a different charger (still not an official one) and all was good.”
“A likely essential for most if not all pi owners. Adapter has a good snug fit on all cables I've tried it on, and connects well to my pi 400. The cheapest adapter of its kind I could find anywhere. Would recommend!”