I've been working with this line manager for a bit over 6 months. He's my boss from the very beginning. He's a horrible micromanager, which is a problem in itself.
However here I would like to ask about a different problem.
He doesn't trust me.
For example, he asks me to create a report on something in an analytics software we use. I create it and send it to him. Then we meet someone specialised in the area of the report and my boss asks the person whether they know how to create the same report. I say: "Hey boss, I know how to create it. I actually sent it to you just yesterday!". The specialist asks how I created it, I describe it, the specialist confirms I've done that correctly and there's no other way to do that and they would do that exactly the same way.
3 days later I learn my boss actually went to another specialist and asked them to organise a meeting on how to create this report! I learn about that since he actually invits me to this meeting because he wants me to learn how to create this report. Basically he expects me to spend more than an hour listening how this report should be created. Of course I contacted this specialist too and asked them whether they have any other way to create the report apart from the way I'm using. The answer was "No! There's definitely no other way to create this report!".
This can last for months and include plenty of people.
I know this sounds as if one of us were totally crazy. I can tell you here, the report was 100% correct. When creating it for the first times I contacted several specialists, including those mentioned above, in order to be 100% sure I create it correctly (and yes, of course I mentioned to my boss that I had).
At the beginning I thought: he doesn't know me, I need to convince him I know what I'm doing. But it has been 6 months. And he does that with each and every topic, not just this one report. And I'm actually an experienced hire, not a recent graduate. Actually in many cases I could teach the people he contacts to confirm that I do something correctly how to do things, as I have more experience.
What ways are there to build trust or just deal with this situation better because for now my work is simply incredibly inefficient and I've been feeling extremely stressed out because of that?