@SGill are you able to test this? The new font-handling on the test site supports a few different fonts for Assamese, such as Lohit Assamese: https://wsexport-test.wmflabs.org/?fonts=Lohit-Assamese&lang=as

Other fonts such as Noto Serif Bengali are also reporting as supporting Assamese.

(Also, are the issues here all font-related, or are there other things at play?)

It would be really helpful if folks always included testcase links so retesting does not rely on individuals. See https://www.mediawiki.org/wiki/How_to_report_a_bug

This seems to be about https://as.wikisource.org/wiki/পৃষ্ঠা:জ্ঞান-মালা.djvu/১৩ .

Using https://wsexport.wmflabs.org/?lang=as&page=পৃষ্ঠা%3Aজ্ঞান-মালা&format=pdf-a5&fonts=Noto+Serif+Bengali this looks fixed when it comes to the font:

@Dibya are you able to test this?

No reply in six weeks; shall we resolve this?

@Aklapper Yes, Let's resolve it. I tested and things look good to me now.

I'd say feel free to set the status of this task to "Resolved" via the Add Action... → Change Status dropdown then (though that would set you as assignee, if you don't want that you can in addition Add Action... → Assign / Claim and leave that blank). Thanks! :)