I too am having a head phone jackbproblem. Since the first update. Just bought the phone in may 3rd. Not sure if that is related to software update or a hardware issue. I need to insert headphone multiple times for it to work.
I too bought my phone on 5th may...and after the recent update for security patch may 2018 it's reacting like this.
I consulted the support chat(Moin).And he said there might be a bug in the software...and would be resolved very soon.Very upset with this defect.