Error in Report and might be time to clean up my QBks data [Mac Desktop 2019]

I was printing out a P&L report on a category/account and after reviewing it I could see there were errors == the $$ numbers were okay but the appropriate check # [and supporting data] was not == For instance, a check on 1/13 was not #6205 but 6241 -- in the list of checks and Register the ## was correct but not in the report created - see attached image.  I need to have the correct check numbers associated with the appropriate checks and dates = as. you can see from this printout that's not happening.  [the correction is in the spreadsheet = no need to correct in QBks but definitely the report is in error.

I also probably need to do a clean up of the QBks data -- I haven't since 2015 and really don't need that historical data at my fingertips so I would like to at least bring it up to 2018 or 2019 =-=- never done that before and need to know how.