Try looking at percentages.
I don't think you have said what the take home pay is, so let's say it is £6000 a month.
£1400 mortgage is under 25% of take home pay, so that's fine.
£800 childcare is a bit over 13%, so sounds low, I would have expected that to be higher.
Housing costs... utilities, council tax, parking permit... that is probably under 10%.
Essential travel costs... to/from work, to/from supermarket. Look at what that is costing.
With larger income, you often have larger expenses, so looking at percentages can sometimes help to identify areas where your spending seems disproportionately high, or low.
Some areas though you don't want to do on percentage, such as food, as someone on low income would spend a high percentage on food, whereas someone on high income their food spend should be a smaller percentage. This is essential food, not going out to restaurants, not shopping at a high end store when there is a budget store around the corner.
Track everything you spend, to the penny, for several months. Everytime anyone pays for something, write it down... what it is, how much. Then you can apply categories.
Don't forget that somethings only occur once a year (car service and MOT), insurance premiums paid annually, and you may have some that occur once every few months.
You can use a simple spreadsheet to track, or a notebook, or whatever you find works... get a receipt each time you buy something and collect the receipts. Write the spend down as soon as possible following the spend... that helps you know what you have spent and reminds your brain that you have spent money, as tap card does not register much pain in your brain. If you need a spreadsheet for tracking, you can find templates online, such as in free budgeting courses, Meaningful Academy: Financial Foundations.
You may have some large expense you have not mentioned, but maybe the problem is that you have a lot of small expenses that you are not tracking, so not aware they are happening.