Adobe PDF Encoding Error

We're creating multingual collateral and getting encoding error when making PDF accessible. This is using Adobe Tamil as typeface. Interesting to note is the same word appears throughout the same document but is fine. Also, the encoding errors are on words using the Adobe Tamil Bold.

I've already tried everything here and beyond:

Create and verify PDF accessibility, Acrobat Pro (adobe.com)

Thanks for your help.

P.S. Original translated text passes in Word and PDF with no issues.

Thanks!