Well I don't know much about your bounty manager and I believe he is a new campaign manager maybe he decides to leave after receiving huge pay out from tokens because this is what most of the hunters do pass through manager received unexpected amount and close their telegram group and made away with the funds, this is were trust lays, most people do not join some bounty's due to either the manager is not known and can never be trusted with huge amount while some reputable manager do pay out to their hunters.
My suggestion is that since your manager has not been active for long time now you have to endure more to see if he would come online and again, if your telegram ban or you are restricted from Post in the bounty group and project group seek for another telegram account then you can used it to track all the activities of the project including that of the bounty manager.
Once again, thank you, friend, for your help and explanation, which can provide enlightenment for me and my fellow Bounty participants. It's true that he has only been Bounty Manager twice, because the first time he paid correctly, I felt that there would be no problems with the next bounty. I will, of course, pay attention to the suggestions and input you give as best as possible to be able to get certainty about this bounty.