Azure Timer Trigger Function fails when you have multiple Functions in the same instance

I have an Azure Function solution using Azure App Service Plan with about 20 functions inside. These functions run continuously and the Time Triggers are different for each one. The point is, after a while, some of them just stop working.

I have already done the following things:

- Set ALWAYS ON
- Configure WEBSITE_USE_PLACEHOLDER to 0
- Define functions as Async

The deployment method that I use is Azure DevOps.

The only way that I could handle it is defining a single WebApp for each function. This action give us an idea that the problem is not in my code.

However this is impossible to deal considering the number of functions I have.

Any tips to solve this?