Constant value of the number of requests per second in ms loadtest'e?

Question

Microsoft

There is ms loadtest, consisting of a dozen webtests.
Load strategy - Constant number of virtual users. The paradox is that when the number of users changes, the number of requests per second (rps) does not increase.
For example:
10 users give an average of 80 rps
20 users give an average of 80 rps
50 users give an average of 80 rps
Naturally, with an increase in the number of users, the duration of the response increases, and with 500 users, the web application returns errors due to the response timeout.
Question : Is it possible to implement the required load using ms loadtesta'? (If yes, how?)
PS In a test mix, you can use the "Test mix based on user pace" model, setting the value "Tests per user per hour" for each test. If I understand correctly, then with such a strategy, one user with one test in the set with the value "Tests per user per hour"=3600 should run exactly 1 rps. But running such a test for a minute gives not 60 requests, but 52. (The value may deviate by a couple of requests). If we change the value "Tests per user per hour"=3600000 in such a test, then theoretically the rps value should be 1000. Alas, this approach did not give the expected results.