Stopped being OE 2 months ago but still overpaying tax, what do I do?

Hi,

So I was OE for a month where I had two jobs overlap. Last month I saw my primary job had its pay significantly taxed more than usual, I assumed because HMRC predicted my income. But this month it’s happened again, despite 2 months of just a single income.

It’s now over £1.5k I’ve over paid in tax. I’ve registered with HMRC but don’t see anything that would let me fix the tax code?

What should I do?