GSTR-3B Sales and Tax Liability Correction

In the Jan–Mar quarter, client had mistakenly reported B2B sales as B2C in GSTR-1. Later, in the Apr–Jun GSTR-1, those invoices were added as B2B in Table 4 amending the old B2C entry in Table 9. Now, the tax liability is showing again in GSTR-3B for Apr–Jun, even though the tax was already paid in Jan–Mar. How to correct this in GSTR-3B now?