Hello Tim,
Please let us know where blubrry referrers to use feedvalidator.org? We removed links to it years ago because it does not support HTTPS and does not understand google play or the latest iTunes tags. validator.w3.org uses the same code that feedvalidator.org uses, albeit on a newer server it still does not accept https:// URLs in values, which is problematic since we’re now supposed to all be using HTTPS. As Shawn said, these validators are not helpful for today’s podcast feeds. Also important to note that these validators check syntax of the feed, they do not check podcast specifics, firewall issues, feed size limitations, HTTP head request support, etc… There are more to podcast feeds than just the syntax.
Two good podcast feed valdaitors for future reference: https://castfeedvalidator.com/ and https://podba.se/validate/ Both validators with your feed check out ok. I then checked our internal validator and your feed also checks ok there.
I checked your SSL cert and that checks out ok, so that should not be an issue. Your feed size is at 214Kb which is ok, 500Kb or more can cause delays with directories updating your listing but you’re within that limit.
I looked up your podcast on iTunes: https://itunes.apple.com/us/podcast/disrupting-japan/id923817924?mt=2 It is using a different feed address than the one you quoted: https://www.disruptingjapan.com/feed/podcast/ Note, you cannot re-submit the same podcast to iTunes with a different feed URL, you have to change the title for a new feed otherwise iTunes will reject it with a “Can’t submit your feed. Your feed was previously submitted.” error.
What other directories/services are giving you errors and what are the error messages?
As for iTunes podcast connect, what is the error message you get?