Recently started getting General Error 6500 in Zoho Projects API

Recently started getting General Error 6500 in Zoho Projects API

Hello.
We have a program that loops through a list of a few of our projects and fetches the time logs.
This was working for a few months, but about a day or two ago, we noticed that the time entries are no longer being returned. When I run our script manually, I see all the API calls are returning a General Error 6500.

I thought this could be due to the API call limit so I tried with a newly-generated auth token and it worked at first, but when I tried again I see the errors. Strangely it sometimes works for a few calls and then continues returning errors.

I've already done everything I can think of to minimize the number of API calls. Is there something else I can do to resolve this?