Multiple services stale in raw 2.0

Hello, we have several servers each with about 200 hosts, but the problem occurs randomly and so far has happened on two servers, in the first we solved by recreating the site, in the second (which incidentally has only 70 hosts) we are still deciding what to do to solve, specifically this server has version 2.0p9 (I rollback from 2.0p15 to understand if the problem was the update) with:
Hosts 73
Services 3023
Services in Stale 2934

It’s like the scheduler doesn’t work anymore and he doesn’t check the various services anymore.

Thanks in advance.