I did the same, I declined my ITA on 18th July with the expiry date of July 19th thinking there could be a draw on 19th or on July 26th and I will get a new ITA, but there you go, unpredictable CIC..... still waiting for ITA, sitting on 458.....
And on top of all received the FBI PCC on 19th in the evening.
The FBI certificate was taking too long. Would have missed the 90 day mark.
Thought decline and fresh start will keep things clean and straight without LOE n stuff! Not sure if that was a great step given the draw scenario so far.
Many people on this forum who were waiting for the FBI PCC submitted their PR application a few days before their ITA expired. They uploaded all the evidence that they had applied to the FBI and were awaiting results, along with LOE. They were given a 2 month extension by IRCC to upload the FBI police certificate. Wish you had read those threads before taking the hasty decision to decline your ITA. Anyway, good luck. Hope you get your ITA in the next draw.