This seems not to be a WPML issue as it is a character charset issue either from the my SQL database or the plugin that you use to generate the PDF file.
To test if it is WPML or not please do as follows:
- IMPORTANT STEP! Create a backup of your website. Or better approach will be to test this on a copy/staging version of the website to avoid any disruption of a live website.
- Go to WordPress Dashboard > Plugins
- Deactivate WPML and WPML addons
- Go to WordPress Dashboard > Settings > General > Site Language and temporarily change it to Arabic.
- generate the PDF file in Arabic and see if the issue persists.
- If yes that shows the issue can be replicated without even WPML being enabled and you need to check with the plugin you used to generate the PDF files.
- If the issue is not replicable when WPML is deactivated, please provide us with the debug information below:
