Feed is https://voiceoverpodcast.com/feed/mp3 I guess?
This is a tricky one because Apple is often pretty mysterious about it. I assume by “episode URL” they’re talking about e.g. https://voiceoverpodcast.com/2021/01/05/debra-sperling/. That looks fine to me.
First of all I’d contact your host. Your host/server should support HTTP head requests.
In the past, rejections based on missing HTTP Head requests often weren’t even about the Head requests but more about the format of provided episode images. You’re logo at https://evilgeniuscreative.com/voiceoverpodcast/wp-content/uploads/2020/12/HowDidYouDOItLogo3000.jpg looks fine to me though.
Individual episode images like https://i2.wp.com/voiceoverpodcast.com/wp-content/uploads/2021/01/poloroid-tomdheere.jpg?fit=750%2C750&ssl=1 do work too (only 750x750 though), even though it looks like some caching is going on. Do you use some kind of caching or “speed improvement” plugin? What happens if you turn it off and clear all caches?