Need to switch departments because of my sneaky micromanager

I’ve been a clerk at the irs for 7 months & I am wondering if it is possible to switch departments with a bad appraisal.

My new manager who has had it out for me & another coworker did my appraisal last month & told me I was successful but to my surprise it was the complete opposite. She said the appraisal was done by my previous manager (who had no clue what I was talking about when I asked her about it & even told me she was not sure why my appraisal was being done because I have not been with the irs long enough). I’ve caught my manager in many lies so this was no surprise but I would like to switch departments. I do not trust my manager & her micromanaging is a lot to deal with.

I have been trying to work with the union on having them look into my appraisal but it’s been a very slow process.

Is it possible for me to change departments by applying for other roles on the USA job site as if I do not currently work at the irs?