I have chained three queueable classes. Couple of them have callouts and other one is not callout. For both the callout classes execute method execution, "No of queueable jobs added to the queue" is different compared to normal class execute method execution. Have a look at the below images and please let me know why there is difference in number of queueable jobs
See Queueable Apex (emphasis mine):
If you need to run a job after some other processing is done first by another job, you can chain queueable jobs. To chain a job to another job, submit the second job from the execute() method of your queueable class. You can add only one job from an executing job, which means that only one child job can exist for each parent job.