Scanning stuck at 12%

I have been carrying out a recovery and recuva was scanning the disk I wanted to check

It seemed to be going fine then each time I do it it gets stuck ay 12% then the 'time left' keeps getting higher and higher

It says it is still scanning but takes about an hour to get to 12% and then is still at 12% 2 hours later

I cancelled the scan and lots of files had been found and I could recover them which was great but I am guessing there was still lots to recover as the process did not complete properly

Does anyone have any ideas or suggestions - do I just need to keep on waiting?