In the log messages of your feed you see the following warning:
"Missing publication time appeared in {number} items in your feed."
Some items in your feed seem to indicate only the date of publishing but not the time. Most or all of these items might not get posted because RSS Graffiti relies on both the date and time of publication to distinguish newer items from older ones.
If you have control over your feed, then you are probably able to fix this issue by adding time in the publication date field to the feed.
If you are not in control of your feed, then you need to ask the system administrator or developer that controls your feed to add the time in the publication date element to the feed.
If you can't do either of the above then unfortunately your feed may not behave as expected with RSS Graffiti.