My tax return got rejected because either my AGI or Self select PIN from last year does not match IRS records....after checking last years taxes all information was correct?

Entering the prior year agi or the prior year self-select pin are merely a requirement to qualify you for e-filing your current year return.

You might try entering a 0 for your prior year agi to see if it will work and let  you continue with your return.  There are several conditions where IRS says you should use a 0 prior year agi.

At this point, being able to e-file your return is the goal.  Try the $0 and see.

Here is some additional information from IRS:

Special Instructions to Validate Your 2020 Electronic Tax Return

If your 2019 tax return has not yet been processed, enter $0 (zero dollars) for your prior year adjusted gross income (AGI).

If you used the Non-Filers: Enter Payment Info Here tool in 2020 to register for an Economic Impact Payment in 2020, enter $1 as your prior year AGI.

For more information, see Claiming the Recovery Rebate Credit if you aren’t required to file a tax return.

When self-preparing your taxes and filing electronically, you must sign and validate your electronic tax return by entering your prior-year Adjusted Gross Income (AGI) or your prior-year Self-Select PIN.

Generally, tax software automatically enters the information for returning customers.

If you are using a software product for the first time, you may have to enter the information yourself.

Refer to this link for additional information:

IRS link to prior year agi number