Bonus, tax code and monthly PAYE query

Hi, I have a salary of 96k following a pay rise last August. Last year I received a bonus of around £25k in August 22 which tipped me into a new tax bracket. My tax code changed in January to (I think, document not here) 152T. In my April pay I only received £4,600. I called the helpline and was told this is because my projected salary is now around £120k which reduces my tax free allowance, that this was the correct take home for April and will be the same ongoing. However, even with this taken into account, I don't see how my monthly take home should now be this low. Could it be that I pay tax monthly, based on HMRC thinking my monthly salary is pro rated for £120k, so I get taxed on that amount, but am only receiving a monthly gross amount based on 96k from my employer? I was told to complete a self assessment for tax year 22/23 and that I would likely owe around £3k based on having had a pay rise in August which wasn't reflected in my tax code until Jan. So the reduced amount cannot be because of that £3k

Hi KR2023 KR,

Your tax code may have been adjusted with an estimated income of £120k which would remove most of your Personal Allowance.
By doing this we aim to collect the correct amount of tax during the year so that you wouldn't have a bill at the end of the tax year.

Thank you.