Student or Learner
"He has been vomiting since he has been admitted to the hospital" (present perfect continues + present perfect)
"I am not feeling well since I have eaten that fried chicken" (present continues + present perfect)
Till now I knew that "since" must be used with preset perfect. but according to your correction I realized that it's possible. I mean "since" can be used even with simple past tense. lots of mistakes happen by us.