I’m confused by how you can be seeing UD in Arabic at all, since it’s not on the list at https://www.ads-software.com/plugins/updraftplus/ ? According to WordPress’s documentation, if a language does not appear there, it should not appear at all. So, in one sense, your site is actually doing more than WP’s docs say it should.
Anyway – plugins do almost nothing to decide what language they’re loaded in. They just tell WordPress “here is my name”, and that’s it. WordPress core takes all language decisions. (And for this reason, I have very few guesses as to what it could be).
However, UpdraftPlus does abort its own loading if it detects its loading on the front-end; perhaps that is somehow related. In the file wp-content/plugins/updraftplus/updraftplus.php
, if you find the line with the comment…
// The checks here before loading are for performance only - unless one of those conditions is met, then none of the hooks will ever be used
… after that there’s a line with a lot of conditions. If you comment-out that line (i.e. add //
at the beginning), and add after it
if (false)
{
(which means, a condition that will never be fulfilled), and then try it all again, do you then get what you’re expecting?