Custom fields not importing

I’m attempting to import items to custom post types, and first I ran into an issue where the final import page would only import one row and then just sit there forever like it’s processing, but nothing more than the one row would import. Tried several times, but it did the same thing each time. So then I enabled the plugins debug mode to see what it said, but it didn’t show any error, instead it actually imported the posts once debug mode was on. Except it didn’t import any of the custom fields (which is where most of the data is), not a single new row in the post_meta table. Any idea what the issue might be?

https://wordpress.org/plugins/wp-ultimate-csv-importer/