It Turns out the problem was with I was using json_enode to convert the data in to json before inserting it in to database and it was causing the encoding of the characters I have used json_encode($url,JSON_UNESCAPED_UNICODE); and now its working properly.
I found the issue. This was being echoed in the_content and WordPress’s texturize was converting to smartquotes. I’ve disabled that on The Content and that seems to have solved the issue.
Encoding matter – ? instead of € after settings field callback
Plugin won’t output characters with diacritics properly
Encode URL for WhatsApp “click to chat” without loosing accented characters
Special characters in post_title replaced by ‘?’
It has many cases: check the character encoding in wp-config.php. define(‘DB_CHARSET’, ‘utf8’); define(‘DB_COLLATE’, ”); check database character encoding check if the font you use supporting Thai letters
✓ Checkmark Character Encoding Issue In WordPress Editor
Let’s give this a guess out of the blue: Check the encoding of your plugin file. It should be ASCII, also named US-ASCII or ascii-7bit. This ensures that your plugin is most compatible to wordpress installations out there. This information is probably useful for you to find out about the actual encoding of your plugins … Read more
Use the plugin Germanix URL. It converts image names on upload to save characters (and creates much better permalinks than WP).