What work rights did your Tier 4 visa state?
"The maximum amount of part time work a Tier 4 international student can do during
semester time is 20 hours per week if you are studying at degree level or above. If
you are studying at a lower level (e.g. a foundation student) you are limited to 10
hours per week.
You can work full time in vacation periods. University semester dates are available
on the Academic Calendar at
https://www2.ljmu.ac.uk/academiccalendar/If you are completing a course that does not fall within the usual LJMU term dates,
you are limited to a maximum of 20 hours per week as long as you have continuing
academic commitments. For example; if you are enrolled on a postgraduate taught
programme you are not allowed to work full time during the summer while you are
completing the dissertation."