The £87.78 are non taxable deductions made up of the umbrella fee, insurance and ??
You have paid the tax and NI on the gross (gross-company deductions) £609.73
your tax code is 1150L the X denotes not confirmed, the tax you pay is correct for single person allowance.
The holiday pay is I think just smoke and mirrors as you have been paid it in your taxable gross.
i would ask them what the additional pay is of £195.31 and also ask if the holiday is accrued and is it payable upon taking the holiday.
I would then ask the firm if they are JIB registered, if so then the pay rate should reflect JIB rates + holiday. I don’t know what current improver rates are?