8.
There are so many reason for mismatch of ITC between GSTR 2A and Table 8 in GSTR 9
Related outward supply invoices are submitted by the supplier’s GSTR-1 may not file the return. The GSTR-2A will display the status “Not yet filed” in case of such invoices.
Delayed filing of GSTR-1 return by the supplier after the due date will not show in Table 8A in GSTR 9.
Supplier may amend the GSTIN of the Invoice in subsequent month after filing of GSTR 1 then the ITC will reflect in B2BA sheet or Invoices filed wrongly as "Liable to RCM" will not show in Table 8A of the recipient.
Supplier converted from Composite Scheme to Regular Taxpayer Scheme, the date of invoice prior to change regular taxpayer scheme then the ITC relating to those purchase invoices will show in Table 8A of GSTR 9.
Apart from these reason, there may be so may technical issues may be reason to mismatch of ITC between GSTR 2A & Table 8 of GSTR 9.