New episodes are posting to apple podcasts site but not showing up as new episode in Podcast app

iTunes is unable to read your feed, so the Store is showing a cached version of the feed as of the last time it was able to read it. Because of this I can't determin the URL of the feed. The page in your second link provides a link to a feed at

http://www.modernchiropracticmarketing.com/feed/podcast/

However the episodes on that page don't match those in the Store. However the feed episodes appear to. The latest episode in the feed matches the latest in the Store.

Your feed is all on one line which makes it nearly impossible to read. FeedValidator claims to have found an XML error in the form of an invalid character in this line:

<title>Practice Growth with Learned Public Speaking by&nbsp;HOF Speaker Joel Weldon</title>

flagging the 'r' in 'Practice' - I cannot find anything wrong with this, and in any case this episode has been up for some time.

The feed also contains the line

<itunes:new-feed-url>https://www.modernchiropracticmarketing.com/podcasts?format=RSS</itunes:new-feed-url>

which will redirect only iTunes to that URL - which however seems to be the same feed, and iTunes isn't reading that either. That's as far as I can go at the moment. I'll try to look at it again but it won't be today.

Found it - possibly, having finally got XMLGrid.net to work. You have four instances of a title with the code for a non-breaking space inserted, as here:

Practice Growth with Learned Public Speaking by&nbsp;HOF Speaker Joel Weldon

I can't see why you bother to do this, I would have thought a simple space would be OK. However, if you really want to do this, you are not allowed to use a named code like this (with certain exceptions, of which this isn't one) in XML: you must use the numbered entity &#160;

Disallowed characters can break a feed with some readers, so this could well be the problem - though these are old episodes - have you been editing them recently? If it's always been like this it's a bit puzzling. Anyway, you need to track down these four episodes and replace the existing code with either the numerical one or an ordinary space. The re-upload the feed, and try subscribing to it manually in iTunes and see whether the episodes appear. There appear to be two versions of this feed at different URLs so I don't know whether modifying one will also modify the other.

Yes, working in iTunes now.