I inspected your site URl https://lanza.com/salon-locator/ and it reflects you are still on SLP 4.5.07, update to 4.5.09
Premier should be on 4.5.09
experience addon is 4.5.08 and Power is 4.5.08…since SLP is 4.5.07 I do not think you have updated to latest versions.
After you update clear the cache.
How are you importing , i,e Via a CSV file upload or a hosted url? Are your data fields set up correctly, what do you have marked for the Import functions Are you using Power latest version. See screenshot for the import UI
The screenshot I have attached is using Power. Power is much faster than ProPack etc. so I am surprised you are having this difficulty.
Is your server timing out ?
Word Press recommends PHP 5.6 as a minimum, your host is 5.3