Switching VAT accrual to Cash

Switching from accrual to cash in Quickfile simply doesn’t work. When I do this, it includes hundreds of invoices since 2022 on my next VAT return, producing a VAT bill that is 10x what it should be.

Trying to remove all of the incorrect invoices from this return, and then to account manually for what VAT has been accounted for and what has not after the switch looks like an administrative and accounting nightmare to me. I don’t even know where to start. Surely it would be better if the software did this automatically?

Why are all of these invoices even included? They have already been declared on previous returns. I have not received any cash for these invoices during the period in question, so why are they appearing on a cash VAT reurn? I would expect such a return to only include payments that were made during the period - that’s literally what cash accounting means.

Is this a bug?