Yes, this is a serious bug. You can replicate it from any browser using the code below.
Every time I run it, it fetches 180 pages at an average rate of 5.51 calls per second.
On the 181st call I get:
Cross-Origin Request Blocked: The Same Origin Policy disallows reading
the remote resource at
The API results are paged, defaulting to 30 (base) records at a time.
So you need to always check the has_more property and fetch additional pages, if needed.
In your second query, it currently returns 22 records. So you see the "Meta Stack Overflow" result you expect.
However, in your first query, 46 records are available and, because you used the ...
No, this is not a bug.
When paging, you must remember and then combine the results from all pages.
So if you fetch:
...then combine the results you get all 36 sites ...