Currently I have only one slave & one executor
And we want to run upstream and downstream jobs on this single executor

1. Suppose we have upstream job A which triggers downstream job B
2. When upstream job starts running on executor, downstream job B goes into the queue
3. As there is only one executor due to which the downstream job remains in the queue & it doesn't get a chance to run on executor as the executor is busy with running the upstream job. This leads to a deadlock scenario

Is this is an issue or bug in jenkins itself?
If it is not an issue then can someone please provide an appropriate solution for it

I want this to happen:

I want that the job B to run after the job A automatically from the queue on the "same executor",
After job B is done executing, I again want job A to run again, but isn't happening
Note: "there is this limitation that I cannot have multiple executors in my project for doing this"