Slicer not working on embedded report

I have a report that has data betwen Oct-2019 and Feb-2020, I have a date range picker for the slicer which passes over a start and end date, however I am getting varied results with the date ranges.

This is the filter for year-to-date, which returns the correct data

1. 0: {operator: "GreaterThan", value: "2020-01-01T00:00:00.000Z"}
2. 1: {operator: "LessThan", value: "2020-02-14T23:59:59.999Z"}

This is the filter for the financial year, which doesn't work (view remains the same regardless of change in date)

1. 0: {operator: "GreaterThan", value: "2019-03-31T23:00:00.000Z"}
2. 1: {operator: "LessThan", value: "2020-03-31T22:59:59.999Z"}

This is the filter for the last 6 months which doesn't work (as above)

1. 0: {operator: "GreaterThan", value: "2019-07-31T23:00:00.000Z"}
2. 1: {operator: "LessThan", value: "2020-01-31T23:59:59.999Z"}

This is the filter for last 12 months, this returns the expected data

1. 0: {operator: "GreaterThan", value: "2019-02-01T00:00:00.000Z"}
2. 1: {operator: "LessThan", value: "2020-01-31T23:59:59.999Z"}