Ocr pro slow does not show results

I have 2 functioning OCR PRO keys, with fewer than 5 requests per minute, and they provide the result of the image. Previously, using just one key resulted in better performance. However, when I added the 2 additional keys to improve performance and speed, the process became significantly slower.
I am using OCR2 and endpoint 1.
What could be the issue?

Using two or more license keys gives you more conversions and more concurrent connections. The performance should absolutely not get worse.

Can you please tell me what endpoint and what OCR engine you are using?