Belated return ITR2 using new regime

Is there any clarification from the authorities for allowing belated ITR filers to use the new regime for AY 21-22?

If tax due was calculated and paid using the new regime well before the deadline, but returns were not filed in time what is the recourse? Does one need to file belated returns, pay the penalty and also pay the differential amount of tax using the old regime? Any option of relief?

The income tax portal is not accepting new regime for belated returns at this time.