NC.
TL:DR - I want to step down from my volunteer role at work because of a manager but don't want to tell him that. What reason do I give?
Long version
I volunteered for an extra role at work along side my actual job. Two other people do it too. It involves working with customers to order suitable equipment. I write a full report for each consultation. I've only ever had positive feedback from customers and internally. Budget isn't a concern but obviously I apply common sense.
The old lead left and the new one is driving me mad. He now insists on all orders going through him despite us having the authority to order ourselves. He never reads my reports but emails me for every order telling me off and making me justify it. He dislikes certain equipment so it is really difficult to get his OK on it. He has undermined me by telling customers different things to me without reading my report or even talking to me.
The last straw was on Monday. He called me into his office to have a go at me about an order HE misunderstood and then told me he'd ordered something completely different anyway. If he'd just spoken to me, it would have avoided all of this and he would have known the item he actually ordered is not suitable. Or he could have just stayed out of it. The customer will think I ordered it.
I don't know if he is like this with the other two volunteers and can't ask them. One is a gossip/trouble maker and the other works completely different shifts to me.
It's a volunteer role which doesn't affect my real job. I really enjoy it but I don't need the grief/distrust from him so have requested a meeting with him tomorrow to tell him I'm am stepping down. But what reason do I give him? I know I should be honest and tell him, it's his fault but that won't be helpful! I can't cite other work pressures because he knows my actual job doesn't have any. My job is very, very specific and limited so I can't give some rubbish about wanting to focus/develop it either.
I'll have to continue to work indirectly with him in my real job so I need to tread carefully.