This is unusual. In the previous three recessions, the profit share fell, and did not return to the level it hit at the cyclical peak in GDP until some time after the recovery: five quarters after the trough in GDP after the 70s and 80s recessions, and 10 quarters after the 1990-91 recession.
So, why the difference?
One possibility is that sterling’s fall has allowed profit margins to expand; this is perfectly consistent with the fact that it’s had little impact on trade volumes. A second possibility - though Q4 data is not yet available - is that that it is financial companies’ profits that have done well*, helped by low interest rates and other government support. And a third answer - consistent with both these - is that massive government borrowing has helped raise profits; this much is true as a national accounts identity.
Whatever the reason, the capitalist class is resilient to recession.
* Debt write-offs are not included in these numbers.