Why some tasks and bugs numbers in "To do" status looks like this ̶2̶5̶6̶6̶

[Vasiliy_Vedeneev]

In my Jira some work items numbers after same time look like this  - view screenshot 

Wtf? The are in to do status 

[Jack Brickey · Accepted solution]

Hi @Vasiliy_Vedeneev , welcome to the Community. Jira  will cross-out issues once zone issue is done and the Resolution field is set. Note, setting the Resolution field is quite important in Jira when transitioning issues to the Done category. Equally, it is important to clear the field (post function) if an issue is moved out (reopened) of the Done category.

[Vasiliy_Vedeneev]

And what could be the problem if the task is still in status "To do", not Done 

[Jack Brickey]

if you have an issue in the "To do" status that is crossed-out then the resolution is set. Refer to my last sentence of my initial reply.

[Vasiliy_Vedeneev]

Tnx