How to solve the problem of braking in Bitrix24?

Question

Bitrix24

Given:
Bitrik24, boxed version. All latest modules installed.
There is the following problem. In the Kanban mapping, the system (by business process) generates tasks.

If you work with tasks in the Deals card, there are no problems. If tasks are closed from the Kanban display, they close incredibly slowly. Those. the response is this, click on the checkmark to close the task. We wait for 5 - 10 seconds and only then it closes.
The problem is clearly not push and pull, everything else works great.
Plus, in the box settings, I specified Bitrix itself to check Push and pull and the problem remained.
Which, as it were, hints to us that the problem is in the task module.

But what to do next, where to go - I do not know.
I ask to prompt that can be, who faced. Or at least what clarifications I can add to the question to complete the description of the problem.