Sorry if unclear but I begin to understand.
There is a mismatch between what are listed in your plugin and the file really used by the plugin WPPIZZA.
“Loco Translate” is pointing and editing file present in ‘lang’ rep of the plugin (../wp-content/plugins/wppizza/lang) and WordPress use file present in global language rep (../wp-content/languages/plugins).
Something else, WPPIZZA use language file named like “wppizza-locale-xx_XX.po/mo” and “Loco Translate” use file like “wppizza-xx_XX.po/mo”.
Conclusion, WPPIZZA don’t use language file edited and listed into “Loco Translate”.