Task log add to other task

I am working on second task, when i stop the log tracking, it will add time to first task

That is mainly because one may have started the time tracking in the first task. Unless you stop the timer it will keep on logging the time for the first task.

at a time only one task is started

The Teach team had a look at this but they were not able to reproduce the issue.

If in case any other users reports this issue in future, we would reopen this bug report. Currently, I am going ahead and closing this issue.