In our team of several software developers we have two leaders: me (official title: "Team Leader" - recently nominated, technical) and another guy (official tite: "Scrum Master" - this is the case for a few months already, non-technical) - let's call him Frank.
Frank and I have totally different visions of how the team should work in areas such as cooperation with customer, procedures, communication within the team, etc. I find Frank's attitude highly destructive for the team (it might be that he feels the same about my actions :-) ). Eg. he overcomplicates the procedures without any justification (I asked for it and got none) and then sends the mail to the whole team claiming that it was agreed (while what happened really was that we were arguing in front of the team).
Similar thing happened when I tried to do some procedures improvement: I consulted client (who was in favour), consulted Frank (who was in favour) and one other developer (who was also in favour). But then Frank changed his mind, blocked my idea and the customer later said to me that he doesn't understand the situation because the proposed change was good.
Now the question is:
How do I handle these situations to get desired result (Frank does not get into my way)?
Should I talk to our project manager as kind of superior for the two of us (seems obvious, but I doubt if effective)?
Or should I ignore his actions in some areas and try to improve situation in other areas?
Or should I continue building a relationship with customer representative and then mount a common cause against Frank (based on real problem to solve)?
Or should I take any other approach?
Some background about the setup: our team of developers is employed by an outsourcing IT corporation and working for another corporation. Some cultural differences might be involved as customer is from Germany, me from Poland and rest of the team (including Frank, our boss and developers) from Belarus.