(First note the arwiki protection levels from InitialiseSettings.php)

'wgRestrictionLevels' => [
	'default' => [
		'',
		'autoconfirmed', // semi-protection level on
		'sysop',
	],
	'arwiki' => [ '', 'autoconfirmed', 'review', 'sysop' ], // T54109, T146575

This happened with ar:بشار الأسد
This article was review-protected (edit protection) but not move-protected.

Current behavior:

When processing the article, AWB gave a "Page is protected" error and skipped the article (in bot mode).

Expected behavior:

AWB should have edited the article normally.
Since AWB was running under a bot account, it is able to edit review-level protected articles.

Workaround:

I unprotected the said article and ran AWB again on it and it worked perfectly (with the same settings and everything).

AWB 5.10.1.0 SVN 12255

Update:
Another article where the bug occurred is ar:جمال خاشقجي which is review-level protected for both editing and move.
So, it appears that AWB (when running in bot mode) considers that review-protected articles are fully-protected, so, it skips them.