Income tax rebate after 31 dec 2018.

Dear Sir,

If the annual income is less than 3.50 Lakh, rebate of Rs. 2500/- was eligible to claim for FY 2017-18.

But after 31st December, 2018, if we file ITR through Income Tax site's quick ITR, the rebate is NIL & also penalty showing NIL.

Is this right ?? What are the changes implemented by income tax department for filing return for FY 17-18 after 31st december ?