Invoice NOT in 2B but showing in 2A, and supplier has filed correct GSTR-1 for that period

If GSTR-1 is correctly filed + invoice appears in GSTR-2A + tax invoice is valid + goods/services received →

You CAN legally claim ITC even if it is missing in GSTR-2B.

Just maintain documentation for audit/show-cause defense later.

If Gstr1 filed by party after due date, so invoice show in next month of gstr2b or if quarterly return file by party then it will show in GSTR 2b in next month of gstr2b. So you have to take itc as and when it will show other Scn will issue..

Itc taken only as per gstr2b statement.

There was sme error in GSTR2B in that month. The voice never relfected in GSTR2B

1-GSTR2B generate after 13th month of subsequent of return filing month that means if Nov R1 filed by supplier it will be show after 13th Dec. hence GSTR 2A will be showing.
2- Your supplier R1 filed after due date i.e 11 and 13 date of next month ( monthly and quatrtly ) respectively i will be shown in next month GSTR2B